import Miranda 2.066 from upstream

1 files changed, 2376 insertions, 0 deletions

diff --git a/new/reduce.c b/new/reduce.c
new file mode 100644
index 0000000..04f7267
--- /dev/null
+++ b/new/reduce.c
@@ -0,0 +1,2376 @@
+/* MIRANDA REDUCE     */
+/* new SK reduction machine - installed Oct 86 */
+
+/**************************************************************************
+ * Copyright (C) Research Software Limited 1985-90.  All rights reserved. *
+ * The Miranda system is distributed as free software under the terms in  *
+ * the file "COPYING" which is included in the distribution.              *
+ *------------------------------------------------------------------------*/
+
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+struct stat buf;  /* used only by code for FILEMODE, FILESTAT in reduce */
+#include "data.h"
+#include "big.h"
+#include "lex.h"
+extern word debug, UTF8, UTF8OUT;
+#define FST HD
+#define SND TL
+#define BSDCLOCK
+/* POSIX clock wraps around after c. 72 mins */
+#ifdef RYU
+char* d2s(double);
+word d2s_buffered(double, char*);
+#endif
+
+double fa,fb;
+long long cycles=0;
+word stdinuse=0;
+/* int lasthead=0; /* DEBUG */
+
+#define constr_tag(x) hd[x]
+#define idconstr_tag(x) hd[id_val(x)]
+#define constr_name(x)  (tag[tl[x]]==ID?get_id(tl[x]):get_id(pn_val(tl[x])))
+#define suppressed(x) (tag[tl[x]]==STRCONS&&tag[pn_val(tl[x])]!=ID)
+	/* suppressed constructor */
+
+#define isodigit(x) ('0'<=(x) && (x)<='7')
+#define sign(x)  (x)
+#define fsign(x)  ((d=(x))<0?-1:d>0)
+/* ### */          /* functions marked ### contain possibly recursive calls
+		      to reduce - fix later */
+
+compare(a,b)  /* returns -1, 0, 1 as a is less than equal to or greater than
+                 b in the ordering imposed on all data types by the miranda
+                 language -- a and b already reduced */
+              /* used by MATCH, EQ, NEQ, GR, GRE */
+word a,b;
+{ double d;
+ L: switch(tag[a])
+    { case DOUBLE:
+      if(tag[b]==DOUBLE)return(fsign(get_dbl(a)-get_dbl(b)));
+      else return(fsign(get_dbl(a)-bigtodbl(b)));
+      case INT:
+      if(tag[b]==INT)return(bigcmp(a,b));
+      else return(fsign(bigtodbl(a)-get_dbl(b)));
+      case UNICODE: return sign(get_char(a)-get_char(b));
+      case ATOM:
+        if(tag[b]==UNICODE) return sign(get_char(a)-get_char(b));
+	if(S<=a&&a<=ERROR||S<=b&&b<=ERROR)
+	  fn_error("attempt to compare functions");
+	  /* what about constructors - FIX LATER */
+        if(tag[b]==ATOM)return(sign(a-b)); /* order of declaration */
+        else return(-1); /* atomic object always less than non-atomic */
+      case CONSTRUCTOR:
+        if(tag[b]==CONSTRUCTOR)
+	  return(sign(constr_tag(a)-constr_tag(b))); /*order of declaration*/
+        else return(-1); /* atom less than non-atom */
+      case CONS: case AP:
+      if(tag[a]==tag[b])
+        { word temp;
+          hd[a]=reduce(hd[a]);
+          hd[b]=reduce(hd[b]);
+          if((temp=compare(hd[a],hd[b]))!=0)return(temp);
+          a=tl[a]=reduce(tl[a]);
+          b=tl[b]=reduce(tl[b]);
+          goto L; }
+      else if(S<=b&&b<=ERROR)fn_error("attempt to compare functions");
+	   else return(1); /* non-atom greater than atom */
+      default: fprintf(stderr,"\nghastly error in compare\n");
+     }
+  return(0);
+}
+
+force(x) /* ensures that x is evaluated "all the way" */
+word x;   /* x is already reduced */ /* ### */
+{ word h;
+  switch(tag[x])
+    { case AP: h=hd[x];
+	       while(tag[h]==AP)h=hd[h];
+               if(S<=h&&h<=ERROR)return; /* don't go inside functions */
+	       /* what about unsaturated constructors? fix later */
+	       while(tag[x]==AP)
+	            { tl[x]=reduce(tl[x]);
+	              force(tl[x]);
+	              x=hd[x]; }
+	       return;
+      case CONS: while(tag[x]==CONS)
+		      { hd[x]=reduce(hd[x]);
+	                force(hd[x]);
+	                x=tl[x]=reduce(tl[x]); }
+    }
+  return;
+}
+
+head(x)   /* finds the function part of x */
+word x;
+{ while(tag[x]==AP)x= hd[x];
+  return(x);
+}
+
+extern char linebuf[];  /* used as workspace in various places */
+
+/* ### */  /* opposite is str_conv - see lex.c */
+char *getstring(x,cmd)  /* collect Miranda string - x is already reduced */
+word x;
+char *cmd; /* context, for error message */
+{ word x1=x,n=0; 
+  char *p=linebuf;
+  while(tag[x]==CONS&&n<BUFSIZE)
+       n++, hd[x] = reduce(hd[x]), x=tl[x]=reduce(tl[x]);
+  x=x1;
+  while(tag[x]==CONS&&n--)
+       *p++ = hd[x], x=tl[x];
+  *p++ ='\0';
+  if(p-linebuf>BUFSIZE)
+    { if(cmd)fprintf(stderr,
+             "\n%s, argument string too long (limit=%d chars): %s...\n",
+	             cmd,BUFSIZE,linebuf),
+             outstats(),
+             exit(1);
+      else return(linebuf); /* see G_CLOSE */ }
+  return(linebuf); /* very inefficient to keep doing this for filenames etc.
+		   CANNOT WE SUPPORT A PACKED REPRESENTATION OF STRINGS? */
+} /* call keep(linebuf) if you want to save the string */
+
+FILE *s_out=NULL;  /* destination of current output message */
+                   /* initialised in main() */
+#define Stdout 0
+#define Stderr 1
+#define Tofile 2
+#define Closefile 3
+#define Appendfile 4
+#define System 5
+#define Exit 6
+#define Stdoutb 7
+#define Tofileb 8
+#define Appendfileb 9
+  /* order of declaration of constructors of these names in sys_message */
+
+/* ### */
+output(e)  /* "output" is called by YACC (see MIRANDA RULES) to print the 
+	      value of an expression - output then calls "reduce" - so the
+              whole reduction process is driven by the need to print  */
+	   /* the value of the whole expression is a list of `messages' */
+word e;
+{ 
+  extern word *cstack;
+  cstack = &e; /* don't follow C stack below this in gc */
+L:e= reduce(e);
+  while(tag[e]==CONS)
+  { word d;
+    hd[e]= reduce(hd[e]);
+    switch(constr_tag(head(hd[e])))
+    { case Stdout: print(tl[hd[e]]);
+		   break;
+      case Stdoutb: UTF8OUT=0;
+                    print(tl[hd[e]]);
+		    UTF8OUT=UTF8;
+		    break;
+      case Stderr: s_out=stderr; print(tl[hd[e]]); s_out=stdout;
+		   break;
+      case Tofile: outf(hd[e]);
+		   break;
+      case Tofileb: UTF8OUT=0;
+                    outf(hd[e]);
+		    UTF8OUT=UTF8;
+		    break;
+      case Closefile: closefile(tl[hd[e]]=reduce(tl[hd[e]]));
+		      break;
+      case Appendfile: apfile(tl[hd[e]]=reduce(tl[hd[e]]));
+		       break;
+      case Appendfileb: UTF8OUT=0;
+                        apfile(tl[hd[e]]=reduce(tl[hd[e]]));
+			UTF8OUT=UTF8;
+		        break;
+      case System: system(getstring(tl[hd[e]]=reduce(tl[hd[e]]),"System"));
+                   break;
+      case Exit:     { word n=reduce(tl[hd[e]]);
+		       if(tag[n]==INT)n=digit0(n);
+		       else word_error("Exit");
+		       outstats(); exit(n); }
+      default: fprintf(stderr,"\n<impossible event in output list: ");
+               out(stderr,hd[e]);
+               fprintf(stderr,">\n"); }
+    e= tl[e]= reduce(tl[e]);
+  }
+  if(e==NIL)return;
+  fprintf(stderr,"\nimpossible event in output\n"),
+     putc('<',stderr),out(stderr,e),fprintf(stderr,">\n");
+  exit(1);
+}
+
+/* ### */
+print(e) /* evaluate list of chars and send to s_out */
+word e;
+{ e= reduce(e);
+  while(tag[e]==CONS && is_char(hd[e]=reduce(hd[e])))
+  { unsigned word c=get_char(hd[e]);
+    if(UTF8)outUTF8(c,s_out); else
+    if(c<256) putc(c,s_out);
+    else fprintf(stderr,"\n warning: non Latin1 char \%x in print, ignored\n",c);
+    e= tl[e]= reduce(tl[e]); }
+  if(e==NIL)return;
+  fprintf(stderr,"\nimpossible event in print\n"),
+   putc('<',stderr),out(stderr,e),fprintf(stderr,">\n"),
+    exit(1);
+}
+
+word outfilq=NIL; /* list of opened-for-output files */
+/* note that this will be automatically reset to  NIL  and  all  files  on  it
+closed at end of expression evaluation, because of the fork-exit structure */
+
+/* ### */
+outf(e)   /*  e is of the form (Tofile f x)  */
+word e;
+{ word p=outfilq; /* have we already opened this file for output? */
+  char *f=getstring(tl[hd[e]]=reduce(tl[hd[e]]),"Tofile");
+  while(p!=NIL && strcmp((char *)hd[hd[p]],f)!=0)p=tl[p];
+  if(p==NIL)  /* new output file */
+  { s_out= fopen(f,"w");
+    if(s_out==NULL)
+      { fprintf(stderr,"\nTofile: cannot write to \"%s\"\n",f);
+	s_out=stdout;
+	return;
+	/* outstats(); exit(1); /* release one policy */
+      }
+    if(isatty(fileno(s_out)))setbuf(s_out,NULL); /*for unbuffered tty output*/
+    outfilq= cons(datapair(keep(f),s_out),outfilq); }
+  else s_out= (FILE *)tl[hd[p]];
+  print(tl[e]);
+  s_out= stdout;
+}
+
+apfile(f) /* open file of name f for appending and add to outfilq */
+word f;
+{ word p=outfilq; /* is it already open? */
+  char *fil=getstring(f,"Appendfile");
+  while(p!=NIL && strcmp((char *)hd[hd[p]],fil)!=0)p=tl[p];
+  if(p==NIL) /* no, so open in append mode */
+    { FILE *s=fopen(fil,"a");
+      if(s==NULL)
+	fprintf(stderr,"\nAppendfile: cannot write to \"%s\"\n",fil);
+      else outfilq= cons(datapair(keep(fil),s),outfilq);
+    }
+  /* if already there do nothing */
+}
+
+closefile(f)  /* remove file of name "f" from outfilq and close stream */
+word f;
+{ word *p= &outfilq; /* is this file open for output? */
+  char *fil=getstring(f,"Closefile");
+  while(*p!=NIL && strcmp((char *)hd[hd[*p]],fil)!=0)p= &tl[*p];
+  if(*p!=NIL)  /* yes */
+    { fclose((FILE *)tl[hd[*p]]);
+	*p=tl[*p]; /* remove link from outfilq */}
+  /* otherwise ignore closefile request (harmless??) */
+}
+
+static word errtrap=0; /* to prevent error cycles - see ERROR below */
+word waiting=NIL;
+/* list of terminated child processes with exit_status - see Exec/EXEC */
+
+/* pointer-reversing SK reduction machine - based on code written Sep 83 */
+
+#define BACKSTOP 020000000000
+#define READY(x) (x)
+#define RESTORE(x)
+/* in this machine the above two are no-ops, alternate definitions are, eg
+#define READY(x) (x+1)
+#define RESTORE(x) x--
+(if using this method each strict comb needs next opcode unallocated)
+   see comment before "ready" switch */
+#define FIELD word
+#define tlptrbit  020000000000
+#define tlptrbits 030000000000
+         /* warning -- if you change this tell `mark()' in data.c */
+#define mktlptr(x)  x |= tlptrbit
+#define mk1tlptr    x |= tlptrbits
+#define mknormal(x) x &= ~tlptrbits
+#define abnormal(x)  ((x)<0)
+/* covers x is tlptr and x==BACKSTOP */
+
+/* control abstractions */
+
+#define setcell(t,a,b)  tag[e]=t,hd[e]=a,tl[e]=b
+#define DOWNLEFT hold=s, s=e, e=hd[e], hd[s]=hold
+#define DOWNRIGHT hold=hd[s], hd[s]=e, e=tl[s], tl[s]=hold, mktlptr(s)
+#define downright if(abnormal(s))goto DONE; DOWNRIGHT
+#define UPLEFT hold=s, s=hd[s], hd[hold]=e, e=hold
+#define upleft if(abnormal(s))goto DONE; UPLEFT
+#define GETARG(a) UPLEFT, a=tl[e]
+#define getarg(a) upleft; a=tl[e]
+#define UPRIGHT mknormal(s), hold=tl[s], tl[s]=e, e=hd[s], hd[s]=hold
+#define lastarg tl[e]
+word reds=0;
+
+/* IMPORTANT WARNING - the macro's
+     `downright;' `upleft;' `getarg;' 
+   MUST BE ENCLOSED IN BRACES when they occur as the body of a control
+   structure (if, while etc.) */
+
+#define simpl(r) hd[e]=I, e=tl[e]=r
+
+#ifdef DEBUG
+word maxrdepth=0,rdepth=0;
+#endif
+
+#define fails(x)   (x==NIL)
+#define FAILURE   NIL
+      /* used by grammar combinators */
+
+/* reduce e to hnf, note that a function in hnf will have head h with
+   S<=h<=ERROR all combinators lie in this range see combs.h */
+FIELD reduce(e)
+FIELD e;
+{ FIELD s=BACKSTOP,hold,arg1,arg2,arg3;
+#ifdef DEBUG
+    if(++rdepth>maxrdepth)maxrdepth=rdepth;
+    if(debug&02)
+    printf("reducing: "),out(stdout,e),putchar('\n');
+#endif
+
+  NEXTREDEX:
+  while(!abnormal(e)&&tag[e]==AP)DOWNLEFT;
+#ifdef HISTO
+  histo(e);
+#endif
+#ifdef DEBUG
+  if(debug&02)
+    { printf("head= ");
+      if(e==BACKSTOP)printf("BACKSTOP");
+      else out(stdout,e);
+      putchar('\n'); }
+#endif
+
+  OPDECODE:
+/*lasthead=e; /* DEBUG */
+  cycles++;
+  switch(e)
+  {
+    case S:        /*  S f g x => f x(g x)  */
+    getarg(arg1);
+    getarg(arg2);
+    upleft;
+    hd[e]=ap(arg1,lastarg); tl[e]=ap(arg2,lastarg);
+    DOWNLEFT;
+    DOWNLEFT;
+    goto NEXTREDEX;
+
+    case B:        /*  B f g x => f(g z)  */
+    getarg(arg1);
+    getarg(arg2);
+    upleft;
+    hd[e]=arg1; tl[e]=ap(arg2,lastarg);
+    DOWNLEFT;
+    goto NEXTREDEX;
+
+    case CB:        /*  CB f g x => g(f z)  */
+    getarg(arg1);
+    getarg(arg2);
+    upleft;
+    hd[e]=arg2; tl[e]=ap(arg1,lastarg);
+    DOWNLEFT;
+    goto NEXTREDEX;
+
+    case C:        /*  C f g x => f x g  */
+    getarg(arg1);
+    getarg(arg2);
+    upleft;
+    hd[e]=ap(arg1,lastarg); tl[e]=arg2;
+    DOWNLEFT;
+    DOWNLEFT;
+    goto NEXTREDEX;
+
+    case Y:        /*  Y h => self where self=(h self)  */
+    upleft;
+    hd[e]=tl[e]; tl[e]=e;
+    DOWNLEFT;
+    goto NEXTREDEX;
+
+    L_K:
+    case K:        /*  K x y => x */
+    getarg(arg1);
+    upleft;
+    hd[e]=I; e=tl[e]=arg1;
+    goto NEXTREDEX;  /* could make eager in first arg */
+
+    L_KI:
+    case KI:              /*  KI x y => y  */
+    upleft;    /* lose first arg  */
+    upleft;
+    hd[e]=I; e=lastarg;  /* ?? */
+    goto NEXTREDEX; /* could make eager in 2nd arg */
+
+    case S1:          /* S1 k f g x => k(f x)(g x) */
+    getarg(arg1);
+    getarg(arg2);
+    getarg(arg3);
+    upleft;
+    hd[e]=ap(arg2,lastarg); 
+    hd[e]=ap(arg1,hd[e]);
+    tl[e]=ap(arg3,lastarg);
+    DOWNLEFT;
+    DOWNLEFT;
+    goto NEXTREDEX;
+
+    case B1:            /* B1 k f g x => k(f(g x)) */
+    getarg(arg1);       /* Mark Scheevel's new B1 */
+    getarg(arg2);
+    getarg(arg3);
+    upleft;
+    hd[e]=arg1;
+    tl[e]=ap(arg3,lastarg);
+    tl[e]=ap(arg2,tl[e]);
+    DOWNLEFT;
+    goto NEXTREDEX;
+
+    case C1:          /* C1 k f g x => k(f x)g */
+    getarg(arg1);
+    getarg(arg2);
+    getarg(arg3);
+    upleft;
+    hd[e]=ap(arg2,lastarg);
+    hd[e]=ap(arg1,hd[e]);
+    tl[e]=arg3;
+    DOWNLEFT;
+    goto NEXTREDEX;
+
+    case S_p:          /*    S_p f g x => (f x) : (g x)  */
+    getarg(arg1);
+    getarg(arg2);
+    upleft;
+    setcell(CONS,ap(arg1,lastarg),ap(arg2,lastarg));
+    goto DONE;
+
+    case B_p:          /*    B_p f g x => f : (g x)      */
+    getarg(arg1);
+    getarg(arg2);
+    upleft;
+    setcell(CONS,arg1,ap(arg2,lastarg));
+    goto DONE;
+
+    case C_p:          /*    C_p f g x => (f x) : g      */
+    getarg(arg1);
+    getarg(arg2);
+    upleft;
+    setcell(CONS,ap(arg1,lastarg),arg2);
+    goto DONE;
+
+    case ITERATE:      /*  ITERATE f x => x:ITERATE f (f x)  */
+    getarg(arg1);
+    upleft;
+    hold=ap(hd[e],ap(arg1,lastarg));
+    setcell(CONS,lastarg,hold);
+    goto DONE;
+
+    case ITERATE1:     /*  ITERATE1 f x => [], x=FAIL
+					=> x:ITERATE1 f (f x), otherwise  */
+    getarg(arg1);
+    upleft;
+    if((lastarg=reduce(lastarg))==FAIL)     /* ### */
+      { hd[e]=I;  e=tl[e]=NIL; }
+    else
+      { hold=ap(hd[e],ap(arg1,lastarg));
+        setcell(CONS,lastarg,hold); }
+    goto DONE;
+
+    case G_RULE:
+    case P:                /* P x y => x:y  */
+    getarg(arg1);
+    upleft;
+    setcell(CONS,arg1,lastarg);
+    goto DONE;
+
+    case U:           /*    U f x => f (HD x) (TL x)
+	                    non-strict uncurry           */
+    getarg(arg1);
+    upleft;
+    hd[e]=ap(arg1,ap(HD,lastarg));
+    tl[e]=ap(TL,lastarg);
+    DOWNLEFT;
+    DOWNLEFT;
+    goto NEXTREDEX;
+
+    case Uf:          /*    Uf f x => f (BODY x) (LAST x)
+                            version of non-strict U for
+                            arbitrary constructors       */
+    getarg(arg1);
+    upleft;
+    if(tag[head(lastarg)]==CONSTRUCTOR)  /* be eager if safe */
+      hd[e]=ap(arg1,hd[lastarg]),
+      tl[e]=tl[lastarg];
+    else
+      hd[e]=ap(arg1,ap(BODY,lastarg)),
+      tl[e]=ap(LAST,lastarg);
+    DOWNLEFT;
+    DOWNLEFT;
+    goto NEXTREDEX;
+
+    case ATLEAST:             /* ATLEAST k f x => f(x-k), isnat x & x>=k
+					       => FAIL, otherwise        */
+			          /* for matching n+k patterns */
+    getarg(arg1);
+    getarg(arg2);
+    upleft;
+    lastarg= reduce(lastarg);          /* ### */
+    if(tag[lastarg]==INT)
+      { hold = bigsub(lastarg,arg1);
+        if(poz(hold))hd[e]=arg2,tl[e]=hold;
+        else hd[e]=I,e=tl[e]=FAIL; }
+    else hd[e]=I,e=tl[e]=FAIL;
+    goto NEXTREDEX;
+
+    case U_:                  /*    U_ f (a:b) => f a b
+                                    U_ f other => FAIL
+                                U_ is a strict version of U(see above)   */
+    getarg(arg1);
+    upleft;
+    lastarg= reduce(lastarg);      /* ### */
+    if(lastarg==NIL)
+    { hd[e]=I;
+      e=tl[e]=FAIL;
+      goto NEXTREDEX; }
+    hd[e]=ap(arg1,hd[lastarg]);
+    tl[e]=tl[lastarg];
+    goto NEXTREDEX;
+
+    case Ug:      /*  Ug k f (k x1 ... xn) => f x1 ... xn, n>=0
+                      Ug k f other => FAIL
+                  Ug is a strict version of U for arbitrary constructor k */
+    getarg(arg1);
+    getarg(arg2);
+    upleft;
+    lastarg= reduce(lastarg);   /* ### */
+    if(constr_tag(arg1)!=constr_tag(head(lastarg)))
+      { hd[e]=I;
+	e=tl[e]=FAIL;
+	goto NEXTREDEX; }
+    if(tag[lastarg]==CONSTRUCTOR) /* case n=0 */
+      { hd[e]=I; e=tl[e]=arg2; goto NEXTREDEX; }
+    hd[e]=hd[lastarg];
+    tl[e]=tl[lastarg];
+    while(tag[hd[e]]!=CONSTRUCTOR)
+	 /* go back to head of arg3, copying spine */
+	 { hd[e]=ap(hd[hd[e]],tl[hd[e]]);
+	   DOWNLEFT; }
+    hd[e]=arg2;   /* replace k with f */
+    goto NEXTREDEX;
+
+    case MATCH:               /*    MATCH a f a => f
+                                    MATCH a f b => FAIL    */
+    upleft;
+    arg1=lastarg=reduce(lastarg);   /* ### */
+    /* note that MATCH evaluates arg1, usually needless, could have second
+       version - MATCHEQ, say */
+    getarg(arg2);
+    upleft;
+    lastarg=reduce(lastarg);   /* ### */
+    hd[e]=I;
+    e=tl[e]=compare(arg1,lastarg)?FAIL:arg2;
+    goto NEXTREDEX;
+
+    case MATCHINT:  /* same but 1st arg is integer literal */
+    getarg(arg1);
+    getarg(arg2);
+    upleft;
+    lastarg=reduce(lastarg);   /* ### */
+    hd[e]=I;
+    e=tl[e]=(tag[lastarg]!=INT||bigcmp(arg1,lastarg))?FAIL:arg2;
+    /* note no coercion from INT to DOUBLE here */
+    goto NEXTREDEX;
+
+    case GENSEQ:   /* GENSEQ (i,NIL) a => a:GENSEQ (i,NIL) (a+i)
+		      GENSEQ (i,b) a => [], a>b=sign
+				     => a:GENSEQ (i,b) (a+i), otherwise
+					where
+					sign =  1, i>=0
+					     = -1, otherwise */
+    GETARG(arg1);
+    UPLEFT;
+    if(tl[arg1]!=NIL&&
+       (tag[arg1]==AP?compare(lastarg,tl[arg1]):compare(tl[arg1],lastarg))>0)
+      hd[e]=I, e=tl[e]=NIL;
+    else hold=ap(hd[e],numplus(lastarg,hd[arg1])),
+	 setcell(CONS,lastarg,hold);
+    goto DONE;
+      /* efficiency hack - tag of arg1 encodes sign of step */
+
+    case MAP:          /* MAP f [] => []
+			  MAP f (a:x) => f a : MAP f x */
+    getarg(arg1);
+    upleft;
+    lastarg=reduce(lastarg);   /* ### */
+    if(lastarg==NIL)
+      hd[e]=I, e=tl[e]=NIL;
+    else hold=ap(hd[e],tl[lastarg]),
+	 setcell(CONS,ap(arg1,hd[lastarg]),hold);
+    goto DONE;
+
+    case FLATMAP:           /* funny version of map for compiling zf exps
+			       FLATMAP f [] => []
+			       FLATMAP f (a:x) => FLATMAP f x, f a=FAIL
+					       => f a ++ FLATMAP f x
+			       (FLATMAP was formerly called MAP1) */
+    getarg(arg1);
+    getarg(arg2);
+ L1:arg2=reduce(arg2);    /* ### */
+    if(arg2==NIL)
+      { hd[e]=I;
+	e=tl[e]=NIL;
+	goto DONE; }
+    hold=reduce(hold=ap(arg1,hd[arg2]));
+    if(hold==FAIL||hold==NIL){ arg2=tl[arg2]; goto L1; }
+    tl[e]=ap(hd[e],tl[arg2]);
+    hd[e]=ap(APPEND,hold);
+    goto NEXTREDEX;
+
+    case FILTER:       /* FILTER f [] => []
+			  FILTER f (a:x) => a : FILTER f x, f a
+					 => FILTER f x, otherwise */
+    getarg(arg1);
+    upleft;
+    lastarg=reduce(lastarg);   /* ### */
+    while(lastarg!=NIL&&reduce(ap(arg1,hd[lastarg]))==False)  /* ### */
+	 lastarg=reduce(tl[lastarg]);   /* ### */
+    if(lastarg==NIL)
+      hd[e]=I, e=tl[e]=NIL;
+    else hold=ap(hd[e],tl[lastarg]),
+	 setcell(CONS,hd[lastarg],hold);
+    goto DONE;
+
+    case LIST_LAST:   /* LIST_LAST x  =>  x!(#x-1)  */
+    upleft;
+    if((lastarg=reduce(lastarg))==NIL)fn_error("last []");  /* ### */
+    while((tl[lastarg]=reduce(tl[lastarg]))!=NIL)    /* ### */
+         lastarg=tl[lastarg];
+    hd[e]=I; e=tl[e]=hd[lastarg];
+    goto NEXTREDEX;
+
+    case LENGTH:   /*  takes length of a list */
+    upleft;
+    { long long n=0; /* problem - may be followed by gc */
+      /* cannot make static because of ### below */
+      while((lastarg=reduce(lastarg))!=NIL)  /* ### */
+	   lastarg=tl[lastarg],n++;
+      simpl(sto_word(n)); }
+    goto DONE;
+
+    case DROP:
+    getarg(arg1);
+    upleft;
+    arg1=tl[hd[e]]=reduce(tl[hd[e]]);  /* ### */
+    if(tag[arg1]!=INT)word_error("drop");
+    { long long n=get_word(arg1);
+      while(n-- >0)
+	if((lastarg=reduce(lastarg))==NIL)  /* ### */
+	  { simpl(NIL); goto DONE; }
+	else lastarg=tl[lastarg]; }
+    simpl(lastarg);
+    goto NEXTREDEX;
+
+    case SUBSCRIPT:   /* SUBSCRIPT i x  =>  x!i  */
+    upleft;
+    upleft;
+    arg1=tl[hd[e]]=reduce(tl[hd[e]]);  /* ### */
+    lastarg=reduce(lastarg);  /* ### */
+    if(lastarg==NIL)subs_error();
+    { long long indx = tag[arg1]==ATOM?arg1:/* small indexes represented directly */
+                       tag[arg1]==INT?get_word(arg1):
+                       word_error("!");
+      /* problem, indx may be followed by gc
+         - cannot make static, because of ### below */
+      if(indx<0)subs_error();
+      while(indx)
+      { lastarg= tl[lastarg]= reduce(tl[lastarg]);   /* ### */
+        if(lastarg==NIL)subs_error();
+        indx--; }
+      hd[e]= I;
+      e=tl[e]=hd[lastarg];  /* could be eager in tl[e] */
+      goto NEXTREDEX; }
+
+    case FOLDL1:      /* FOLDL1 op (a:x) => FOLDL op a x */
+    getarg(arg1);
+    upleft;
+    if((lastarg=reduce(lastarg))!=NIL)   /* ### */
+      { hd[e]=ap2(FOLDL,arg1,hd[lastarg]);
+        tl[e]=tl[lastarg];
+	goto NEXTREDEX; }
+    else fn_error("foldl1 applied to []");
+
+    case FOLDL:       /* FOLDL op r [] => r
+			 FOLDL op r (a:x) => FOLDL op (op r a)^ x
+
+                         ^ (FOLDL op) is made strict in 1st param */
+    getarg(arg1);
+    getarg(arg2);
+    upleft;
+    while((lastarg=reduce(lastarg))!=NIL)   /* ### */
+	 arg2=reduce(ap2(arg1,arg2,hd[lastarg])),   /* ^ ### */
+	 lastarg=tl[lastarg];
+    hd[e]=I, e=tl[e]=arg2;
+    goto NEXTREDEX;
+
+    case FOLDR:       /* FOLDR op r [] => r
+			 FOLDR op r (a:x) => op a (FOLDR op r x) */
+    getarg(arg1);
+    getarg(arg2);
+    upleft;
+    lastarg=reduce(lastarg);   /* ### */
+    if(lastarg==NIL)
+      hd[e]=I, e=tl[e]=arg2;
+    else hold=ap(hd[e],tl[lastarg]),
+	 hd[e]=ap(arg1,hd[lastarg]), tl[e]=hold;
+    goto NEXTREDEX;
+
+    L_READBIN:
+    case READBIN:    /*    READBIN streamptr => nextchar : READBIN streamptr
+                           if end of file,    READBIN file => NIL
+			   READBIN does no UTF-8 conversion        */
+    UPLEFT;          /* gc insecurity - arg is not a heap object */
+    if(lastarg==0) /* special case created by $:- */
+      { if(stdinuse=='-')stdin_error(':');
+        if(stdinuse)
+          { hd[e]=I; e=tl[e]=NIL; goto DONE; }
+        stdinuse=':';
+        tl[e]=(word)stdin; }
+    hold= getc((FILE *)lastarg);
+    if(hold==EOF)
+     {   fclose((FILE *)lastarg);
+	 hd[e]=I;
+         e=tl[e]= NIL;
+         goto DONE; }
+    setcell(CONS,hold,ap(READBIN,lastarg));
+    goto DONE;
+
+    L_READ:
+    case READ:        /*    READ streamptr => nextchar : READ streamptr
+                            if end of file,    READ file => NIL
+    			    does UTF-8 conversion where appropriate     */
+    UPLEFT;           /* gc insecurity - arg is not a heap object */
+    if(lastarg==0) /* special case created by $- */
+      { if(stdinuse==':')stdin_error('-');
+        if(stdinuse)
+          { hd[e]=I; e=tl[e]=NIL; goto DONE; }
+	stdinuse='-';
+	tl[e]=(word)stdin; }
+    hold=UTF8?sto_char(fromUTF8((FILE *)lastarg)):getc((FILE *)lastarg);
+    if(hold==EOF)
+     {   fclose((FILE *)lastarg);
+         hd[e]=I;
+         e=tl[e]= NIL;
+         goto DONE; }
+    setcell(CONS,hold,ap(READ,lastarg));
+    goto DONE;
+
+    L_READVALS:
+    case READVALS:   /*  READVALS (t:fil) f => [], EOF from FILE *f
+				            => val : READVALS t f, otherwise
+			 where val is obtained by parsing lines of
+			 f, and taking next legal expr of type t */
+    GETARG(arg1);
+    upleft;
+    hold=parseline(hd[arg1],(FILE *)lastarg,tl[arg1]);
+    if(hold==EOF)
+     {   fclose((FILE *)lastarg);
+	 hd[e]=I;
+         e=tl[e]= NIL;
+         goto DONE; }
+    arg2=ap(hd[e],lastarg);
+    setcell(CONS,hold,arg2);
+    goto DONE;
+
+    case BADCASE:    /* BADCASE cons(oldn,here_info) => BOTTOM */
+    UPLEFT;
+      { extern word sourcemc;
+	word subject= hd[lastarg];
+		      /* either datapair(oldn,0) or 0 */
+	fprintf(stderr,"\nprogram error: missing case in definition");
+	if(subject) /* cannot do patterns - FIX LATER */
+	  fprintf(stderr," of %s",(char *)hd[subject]);
+	putc('\n',stderr);
+	out_here(stderr,tl[lastarg],1);
+     /* if(sourcemc&&nargs>1)
+	{ int i=2;
+	  fprintf(stderr,"arg%s = ",nargs>2?"s":"");
+	  while(i<=nargs)out(stderr,tl[stackp[-(i++)]]),putc(' ',stderr);
+	  putc('\n',stderr); } /* fix later */
+      }
+    outstats();
+    exit(1);
+
+    case GETARGS:  /* GETARGS 0 => argv  ||`$*' = command line args */
+    UPLEFT;
+    simpl(conv_args());
+    goto DONE;
+
+    case CONFERROR:    /* CONFERROR error_info => BOTTOM */
+    /* if(nargs<1)fprintf(stderr,"\nimpossible event in reduce\n"),
+       exit(1); */
+    UPLEFT;
+    fprintf(stderr,"\nprogram error: lhs of definition doesn't match rhs");
+    /*fprintf(stderr," OF ");
+    out_formal1(stderr,hd[lastarg]); /* omit - names may have been aliased */
+    putc('\n',stderr);
+    out_here(stderr,tl[lastarg],1);
+    outstats();
+    exit(1);
+
+    case ERROR:    /* ERROR error_info => BOTTOM */
+    upleft;
+    if(errtrap)fprintf(stderr,"\n(repeated error)\n");
+    else { errtrap=1;
+           fprintf(stderr,"\nprogram error: ");
+	   s_out=stderr;
+           print(lastarg);    /* ### */
+           putc('\n',stderr); }
+    outstats();
+    exit(1);
+
+    case WAIT:        /* WAIT pid => <exit_status of child process pid> */
+    UPLEFT;
+  { word *w= &waiting; /* list of terminated pid's and their exit statuses */
+    while(*w!=NIL&&hd[*w]!=lastarg)w= &tl[tl[*w]];
+    if(*w!=NIL)hold=hd[tl[*w]],
+	       *w=tl[tl[*w]];  /* remove entry */
+    else { word status;
+	   while((hold=wait(&status))!=lastarg&&hold!= -1)
+		waiting=cons(hold,cons(WEXITSTATUS(status),waiting));
+	   if(hold!= -1)hold=WEXITSTATUS(status); }}
+    simpl(stosmallint(hold));
+    goto DONE;
+
+    L_I:
+/*  case MONOP:  (all strict monadic operators share this code)  */
+    case I:    /* we treat I as strict to avoid I-chains (MOD1) */
+    case SEQ:
+    case FORCE:
+    case HD:
+    case TL:
+    case BODY:
+    case LAST:
+    case EXEC:
+    case FILEMODE:
+    case FILESTAT:
+    case GETENV:
+    case INTEGER:
+    case NUMVAL:
+    case TAKE:
+    case STARTREAD:
+    case STARTREADBIN:
+    case NB_STARTREAD:
+    case COND:
+    case APPEND:
+    case AND:
+    case OR:
+    case NOT:
+    case NEG:
+    case CODE:
+    case DECODE:
+    case SHOWNUM:
+    case SHOWHEX:
+    case SHOWOCT:
+    case ARCTAN_FN: /* ...FN are strict functions of one numeric arg */
+    case EXP_FN:
+    case ENTIER_FN:
+    case LOG_FN:
+    case LOG10_FN:
+    case SIN_FN:
+    case COS_FN:
+    case SQRT_FN:
+    downright;  /* subtask -- reduce arg  */
+    goto NEXTREDEX;
+
+    case TRY:          /* TRY f g x => TRY(f x)(g x)   */
+    getarg(arg1);
+    getarg(arg2);
+    while(!abnormal(s))
+	 { UPLEFT;
+	   hd[e]=ap(TRY,arg1=ap(arg1,lastarg));
+	   arg2=tl[e]=ap(arg2,lastarg); }
+    DOWNLEFT;
+    /* DOWNLEFT; DOWNRIGHT; equivalent to:*/
+    hold=s,s=e,e=tl[e],tl[s]=hold,mktlptr(s); /* now be strict in arg1 */
+    goto NEXTREDEX;
+
+    case FAIL:     /* FAIL x => FAIL */
+    while(!abnormal(s))hold=s,s=hd[s],hd[hold]=FAIL,tl[hold]=0;
+    goto DONE;
+
+/*  case DIOP:   (all strict diadic operators share this code)  */
+    case ZIP:
+    case STEP:
+    case EQ:
+    case NEQ:
+    case PLUS:
+    case MINUS:
+    case TIMES:
+    case INTDIV:
+    case FDIV:
+    case MOD:
+    case GRE:
+    case GR:
+    case POWER:
+    case SHOWSCALED:
+    case SHOWFLOAT:
+    case MERGE:
+    upleft;
+    downright;  /* first subtask -- reduce arg2  */
+    goto NEXTREDEX;
+
+    case Ush:    /*  strict in three args */
+    case STEPUNTIL:
+    upleft;
+    upleft;
+    downright;
+    goto NEXTREDEX;  /* first subtask -- reduce arg3 */
+
+    case Ush1:	/* non-strict version of Ush */
+	        /* Ush1 (k f1...fn) p stuff
+		          => "k"++' ':f1 x1 ...++' ':fn xn, p='\0'
+		          => "(k"++' ':f1 x1 ...++' ':fn xn++")", p='\1'
+			     where xi = LAST(BODY^(n-i) stuff) */
+    getarg(arg1);
+    arg1=reduce(arg1);    /* ### */
+    getarg(arg2);
+    arg2=reduce(arg2);    /* ### */
+    getarg(arg3);
+    if(tag[arg1]==CONSTRUCTOR) /* don't parenthesise atom */
+      { hd[e]=I;
+        if(suppressed(arg1))
+	  e=tl[e]=str_conv("<unprintable>");
+	else e=tl[e]=str_conv(constr_name(arg1));
+	goto DONE; }
+    hold=arg2?cons(')',NIL):NIL;
+    while(tag[arg1]!=CONSTRUCTOR)
+         hold=cons(' ',ap2(APPEND,ap(tl[arg1],ap(LAST,arg3)),hold)),
+         arg1=hd[arg1],arg3=ap(BODY,arg3);
+    if(suppressed(arg1))
+      { hd[e]=I; e=tl[e]=str_conv("<unprintable>"); goto DONE; }
+    hold=ap2(APPEND,str_conv(constr_name(arg1)),hold);
+    if(arg2)
+      { setcell(CONS,'(',hold); goto DONE; }
+    else { hd[e]=I; e=tl[e]=hold; goto NEXTREDEX; }
+
+    case MKSTRICT:  /* MKSTRICT k f x1 ... xk => f x1 ... xk, xk~=BOT */
+    GETARG(arg1);
+    getarg(arg2);
+    { word i=arg1;
+      while(i--) { upleft; } }
+    lastarg=reduce(lastarg);         /* ### */
+    while(--arg1)  /* go back towards head, copying spine */
+	 { hd[e]=ap(hd[hd[e]],tl[hd[e]]);
+	   DOWNLEFT;}
+    hd[e]=arg2;  /* overwrite (MKSTRICT k f) with f */
+    goto NEXTREDEX;
+
+    case G_ERROR:    /* G_ERROR f g toks = (g residue):[], fails(f toks)
+		                         = f toks, otherwise */
+    GETARG(arg1);
+    GETARG(arg2);
+    upleft;
+    hold=ap(arg1,lastarg);
+    hold=reduce(hold);          /* ### */
+    if(!fails(hold))
+      { hd[e]=I; e=tl[e]=hold; goto DONE; }
+    hold=g_residue(lastarg);
+    setcell(CONS,ap(arg2,hold),NIL);
+    goto DONE;
+
+    case G_ALT:      /* G_ALT f g toks = f toks, !fails(f toks)
+                                       = g toks, otherwise  */
+    GETARG(arg1);
+    GETARG(arg2);
+    upleft;
+    hold=ap(arg1,lastarg);
+    hold=reduce(hold);         /* ### */
+    if(!fails(hold))
+      { hd[e]=I; e=tl[e]=hold; goto DONE; }
+    hd[e]=arg2;
+    DOWNLEFT;
+    goto NEXTREDEX;
+
+    case G_OPT:         /* G_OPT f toks = []:toks, fails(f toks)
+					= [a]:toks', otherwise
+					  where
+					  a:toks' = f toks */
+    GETARG(arg1);
+    upleft;
+    hold=ap(arg1,lastarg);
+    hold=reduce(hold);         /* ### */
+    if(fails(hold))
+      setcell(CONS,NIL,lastarg);
+    else setcell(CONS,cons(hd[hold],NIL),tl[hold]);
+    goto DONE;
+
+    case G_STAR:   /* G_STAR f toks => []:toks, fails(f toks)
+			            => ((a:FST z):SND z)
+		      	               where 
+			               a:toks' = f toks
+			               z = G_STAR f toks'
+		   */
+    GETARG(arg1);
+    upleft;
+    hold=ap(arg1,lastarg);
+    hold=reduce(hold);          /* ### */
+    if(fails(hold))
+      { setcell(CONS,NIL,lastarg); goto DONE; }
+    arg2=ap(hd[e],tl[hold]);  /* called z in above rules */
+    tag[e]=CONS;hd[e]=cons(hd[hold],ap(FST,arg2));tl[e]=ap(SND,arg2);
+    goto DONE;
+
+    /* G_RULE has same action as P */
+
+    case G_FBSTAR: /* G_FBSTAR f toks 
+		      = I:toks, if fails(f toks)
+		      = G_SEQ (G_FBSTAR f) (G_RULE (CB a)) toks', otherwise
+		        where a:toks' = f toks
+		   */
+    GETARG(arg1);
+    upleft;
+    hold=ap(arg1,lastarg);
+    hold=reduce(hold);          /* ### */
+    if(fails(hold))
+      { setcell(CONS,I,lastarg); goto DONE; }
+    hd[e]=ap2(G_SEQ,hd[e],ap(G_RULE,ap(CB,hd[hold]))); tl[e]=tl[hold];
+    goto NEXTREDEX;
+
+    case G_SYMB:        /* G_SYMB t ((t,s):toks) = t:toks
+			   G_SYMB t toks = FAILURE  */
+    GETARG(arg1); /* will be in NF */
+    upleft;
+    lastarg=reduce(lastarg);          /* ### */
+    if(lastarg==NIL)
+      { hd[e]=I,e=tl[e]=NIL; goto DONE; }
+    hd[lastarg]=reduce(hd[lastarg]);          /* ### */
+    hold=ap(FST,hd[lastarg]);
+    if(compare(arg1,reduce(hold)))            /* ### */
+      hd[e]=I,e=tl[e]=FAILURE;
+    else setcell(CONS,arg1,tl[lastarg]);
+    goto DONE;
+
+    case G_ANY:         /* G_ANY ((t,s):toks) = t:toks
+			   G_ANY [] = FAILURE   */
+    upleft;
+    lastarg=reduce(lastarg);          /* ### */
+    if(lastarg==NIL)
+      hd[e]=I,e=tl[e]=FAILURE;
+    else setcell(CONS,ap(FST,hd[lastarg]),tl[lastarg]);
+    goto DONE;
+
+    case G_SUCHTHAT:     /* G_SUCHTHAT f ((t,s):toks) = t:toks, f t
+			    G_SUCHTHAT f toks = FAILURE  */
+    GETARG(arg1);
+    upleft;
+    lastarg=reduce(lastarg);          /* ### */
+    if(lastarg==NIL)
+      { hd[e]=I,e=tl[e]=FAILURE; goto DONE; }
+    hold=ap(FST,hd[lastarg]);
+    hold=reduce(hold);                /* ### */
+    if(reduce(ap(arg1,hold))==True)          /* ### */
+      setcell(CONS,hold,tl[lastarg]);
+    else hd[e]=I,e=tl[e]=FAILURE;
+    goto DONE;
+      
+
+    case G_END:         /* G_END [] = []:[]
+			   G_END other = FAILURE */
+    upleft;
+    lastarg=reduce(lastarg);
+    if(lastarg==NIL)
+      setcell(CONS,NIL,NIL);
+    else hd[e]=I,e=tl[e]=FAILURE;
+    goto DONE;
+
+    case G_STATE:       /* G_STATE ((t,s):toks) = s:((t,s):toks)
+		           G_STATE [] = FAILURE   */
+    upleft;
+    lastarg=reduce(lastarg);          /* ### */
+    if(lastarg==NIL)
+      hd[e]=I,e=tl[e]=FAILURE;
+    else setcell(CONS,ap(SND,hd[lastarg]),lastarg);
+    goto DONE;
+
+    case G_SEQ:         /* G_SEQ f g toks = FAILURE, fails(f toks)
+					  = FAILURE, fails(g toks')
+					  = b a:toks'', otherwise
+					    where
+					    a:toks' = f toks
+					    b:toks'' = g toks' */
+    GETARG(arg1);
+    GETARG(arg2);
+    upleft;
+    hold=ap(arg1,lastarg);
+    hold=reduce(hold);          /* ### */
+    if(fails(hold))
+      { hd[e]=I,e=tl[e]=FAILURE; goto DONE; }
+    arg3=ap(arg2,tl[hold]);
+    arg3=reduce(arg3);          /* ### */
+    if(fails(arg3))
+      { hd[e]=I,e=tl[e]=FAILURE; goto DONE; }
+    setcell(CONS,ap(hd[arg3],hd[hold]),tl[arg3]);
+    goto DONE;
+
+    case G_UNIT:   /* G_UNIT toks => I:toks */
+    upleft;
+    tag[e]=CONS,hd[e]=I;
+    goto DONE;
+    /* G_UNIT is right multiplicative identity, equivalent (G_RULE I) */
+
+    case G_ZERO:   /* G_ZERO toks => FAILURE */
+    upleft;
+    simpl(FAILURE);
+    goto DONE;
+    /* G_ZERO is left additive identity */
+
+    case G_CLOSE:     /* G_CLOSE s f toks = <error s>, fails(f toks')
+				          = <error s>, toks'' ~= NIL
+					  = a, otherwise
+					    where
+					    toks' = G_COUNT toks
+					    a:toks'' = f toks' */
+    GETARG(arg1);
+    GETARG(arg2);
+    upleft;
+    arg3=ap(G_COUNT,lastarg);
+    hold=ap(arg2,arg3);
+    hold=reduce(hold);          /* ### */
+    if(fails(hold) /* ||(tl[hold]=reduce(tl[hold]))!=NIL  /* ### */
+      )            /* suppress to make parsers lazy by default 13/12/90 */
+      { fprintf(stderr,"\nPARSE OF %sFAILS WITH UNEXPECTED ",
+		getstring(arg1,0));
+	arg3=reduce(tl[g_residue(arg3)]);
+	if(arg3==NIL)
+	  fprintf(stderr,"END OF INPUT\n"),
+	  outstats(),
+	  exit(1);
+	hold=ap(FST,hd[arg3]);
+	hold=reduce(hold);
+	fprintf(stderr,"TOKEN \"");
+	if(hold==OFFSIDE)fprintf(stderr,"offside"); /* not now possible */
+          { char *p=getstring(hold,0);
+	    while(*p)fprintf(stderr,"%s",charname(*p++)); }
+	fprintf(stderr,"\"\n");
+	outstats();
+	exit(1); }
+    hd[e]=I,e=tl[e]=hd[hold];
+    goto NEXTREDEX;
+/* NOTE the atom OFFSIDE differs from every string and is used as a
+   pseudotoken when implementing the offside rule - see `indent' in prelude */
+
+    case G_COUNT:       /* G_COUNT NIL => NIL
+			   G_COUNT (t:toks) => t:G_COUNT toks */
+    /* G_COUNT is an identity operation on lists - its purpose is to mark
+       last token examined, for syntax error location purposes */
+    upleft;
+    if((lastarg=reduce(lastarg))==NIL)   /* ### */
+      { hd[e]=I; e=tl[e]=NIL; goto DONE; }
+    setcell(CONS,hd[lastarg],ap(G_COUNT,tl[lastarg]));
+    goto DONE;
+
+/*  Explanation of %lex combinators.  A lex analyser is of type
+
+	lexer == [char] -> [alpha]
+
+    At top level these are of the form (LEX_RPT f) where f is of type
+
+	lexer1 == startcond -> [char] -> (alpha,startcond,[char])
+
+    A lexer1 is guaranteed to return a triple (if it returns at all...)
+    and is built using LEX_TRY.
+
+	LEX_TRY [(scstuff,(matcher [],rule))*] :: lexer1
+        rule :: [char] -> alpha
+        matcher :: partial_match -> input -> {(alpha,input') | []}
+
+    partial_match and input are both [char] and [] represents failure.
+    The other lex combinators - LEX_SEQ, LEX_OR, LEX_CLASS etc., all
+    create and combine objects of type matcher.
+
+    LEX_RPT1 is a deviant version that labels the input characters
+    with their lexical state (row,col) using LEX_COUNT - goes with
+    LEX_TRY1 which feeds the leading state of input to each rule.
+
+*/
+
+    case LEX_RPT1: /* LEX_RPT1 f s x => LEX_RPT f s (LEX_COUNT0 x)
+	           i.e. LEX_RPT1 f s => B (LEX_RPT f s) LEX_COUNT0
+		   */
+    GETARG(arg1);
+    UPLEFT;
+    hd[e]=ap(B,ap2(LEX_RPT,arg1,lastarg)); tl[e]=LEX_COUNT0;
+    DOWNLEFT;
+    DOWNLEFT;
+    goto NEXTREDEX;
+
+    case LEX_RPT:       /* LEX_RPT f s [] => []
+			   LEX_RPT f s x  => a : LEX_RPT f s' y
+					     where
+					     (a,s',y) = f s x 
+			   note that if f returns a result it is
+			   guaranteed to be a triple
+			*/
+    GETARG(arg1);
+    GETARG(arg2);
+    upleft;
+    if((lastarg=reduce(lastarg))==NIL)   /* ### */
+      { hd[e]=I; e=tl[e]=NIL; goto DONE; }
+    hold=ap2(arg1,arg2,lastarg);
+    arg1=hd[hd[e]];
+    hold=reduce(hold);
+    setcell(CONS,hd[hold],ap2(arg1,hd[tl[hold]],tl[tl[hold]]));
+    goto DONE;
+
+    case LEX_TRY:
+    upleft;
+    tl[e]=reduce(tl[e]);  /* ### */
+    force(tl[e]);
+    hd[e]=LEX_TRY_;
+    DOWNLEFT;
+    /* falls thru to next case */
+
+    case LEX_TRY_:
+ /* LEX_TRY ((scstuff,(f,rule)):alt) s x => LEX_TRY alt s x, if f x = []
+				         => (rule (rev a),s,y), otherwise
+					    where
+					    (a,y) = f x
+    LEX_TRY [] s x => BOTTOM
+ */
+    GETARG(arg1);
+    GETARG(arg2);
+    upleft;
+L2: if(arg1==NIL)lexfail(lastarg);
+    if(hd[hd[hd[arg1]]]&&!member(hd[hd[hd[arg1]]],arg2))
+      { arg1=tl[arg1]; goto L2; } /* hd[scstuff] is 0 or list of startconds */
+    hold=ap(hd[tl[hd[arg1]]],lastarg);
+    if((hold=reduce(hold))==NIL)        /* ### */
+      { arg1=tl[arg1]; goto L2; }
+    setcell(CONS,ap(tl[tl[hd[arg1]]],ap(DESTREV,hd[hold])),
+		 cons(tl[hd[hd[arg1]]]?tl[hd[hd[arg1]]]-1:arg2,tl[hold]));
+	        /* tl[scstuff] is 1 + next start condition (0 = no change) */
+    goto DONE;
+
+    case LEX_TRY1:
+    upleft;
+    tl[e]=reduce(tl[e]);  /* ### */
+    force(tl[e]);
+    hd[e]=LEX_TRY1_;
+    DOWNLEFT;
+    /* falls thru to next case */
+
+    case LEX_TRY1_:
+ /* LEX_TRY1 ((scstuff,(f,rule)):alt) s x => LEX_TRY1 alt s x, if f x = []
+				          => (rule n (rev a),s,y), otherwise
+				             where
+				             (a,y) = f x
+				             n = lexstate(x)
+    ||same as LEX_TRY but feeds lexstate to rule
+ */
+    GETARG(arg1);
+    GETARG(arg2);
+    upleft;
+L3: if(arg1==NIL)lexfail(lastarg);
+    if(hd[hd[hd[arg1]]]&&!member(hd[hd[hd[arg1]]],arg2))
+      { arg1=tl[arg1]; goto L3; } /* hd[scstuff] is 0 or list of startconds */
+    hold=ap(hd[tl[hd[arg1]]],lastarg);
+    if((hold=reduce(hold))==NIL)        /* ### */
+      { arg1=tl[arg1]; goto L3; }
+    setcell(CONS,ap2(tl[tl[hd[arg1]]],lexstate(lastarg),ap(DESTREV,hd[hold])),
+		 cons(tl[hd[hd[arg1]]]?tl[hd[hd[arg1]]]-1:arg2,tl[hold]));
+	        /* tl[scstuff] is 1 + next start condition (0 = no change) */
+    goto DONE;
+
+    case DESTREV:  /* destructive reverse - used only by LEX_TRY */
+    GETARG(arg1);  /* known to be an explicit list */
+    arg2=NIL; /* to hold reversed list */
+    while(arg1!=NIL)
+	 { if(tag[hd[arg1]]==STRCONS) /* strip off lex state if present */
+	     hd[arg1]=tl[hd[arg1]];
+	   hold=tl[arg1],tl[arg1]=arg2,arg2=arg1,arg1=hold; }
+    hd[e]=I; e=tl[e]=arg2;
+    goto DONE;
+
+    case LEX_COUNT0:  /* LEX_COUNT0 x => LEX_COUNT (state0,x) */
+    upleft;
+    hd[e]=LEX_COUNT; tl[e]=strcons(0,tl[e]);
+    DOWNLEFT;
+    /* falls thru to next case */
+
+    case LEX_COUNT: /* LEX_COUNT (state,[]) => []
+		       LEX_COUNT (state,(a:x)) => (state,a):LEX_COUNT(state',a)
+		       where
+		       state == (line_no*256+col_no)
+		    */
+    GETARG(arg1);
+    if((tl[arg1]=reduce(tl[arg1]))==NIL)   /* ### */
+      { hd[e]=I; e=tl[e]=NIL; goto DONE; }
+    hold=hd[tl[arg1]]; /* the char */
+    setcell(CONS,strcons(hd[arg1],hold),ap(LEX_COUNT,arg1));
+    if(hold=='\n')hd[arg1]=(hd[arg1]>>8)+1<<8; 
+    else { word col = hd[arg1]&255;
+	   col = hold=='\t'?(col/8+1)*8:col+1;
+	   hd[arg1] = hd[arg1]&(~255)|col; }
+    tl[arg1]=tl[tl[arg1]];
+    goto DONE;
+
+#define lh(x) (tag[hd[x]]==STRCONS?tl[hd[x]]:hd[x])
+  /* hd char of possibly lex-state-labelled string */
+
+    case LEX_STRING: /*  LEX_STRING [] p x => p : x
+			 LEX_STRING (c:s) p (c:x) => LEX_STRING s (c:p) x
+			 LEX_STRING (c:s) p other => []
+		     */
+    GETARG(arg1);
+    GETARG(arg2);
+    upleft;
+    while(arg1!=NIL)
+         { if((lastarg=reduce(lastarg))==NIL||lh(lastarg)!=hd[arg1]) /* ### */
+             { hd[e]=I; e=tl[e]=NIL; goto DONE; }
+	   arg1=tl[arg1]; arg2=cons(hd[lastarg],arg2); lastarg=tl[lastarg]; }
+    tag[e]=CONS; hd[e]=arg2;
+    goto DONE;
+
+    case LEX_CLASS: /* LEX_CLASS set p (c:x) => (c:p) : x, if c in set
+		       LEX_CLASS set p   x   => [], otherwise
+		    */
+    GETARG(arg1);
+    GETARG(arg2);
+    upleft;
+    if((lastarg=reduce(lastarg))==NIL||         /* ### */
+       (hd[arg1]==ANTICHARCLASS?memclass(lh(lastarg),tl[arg1])
+                               :!memclass(lh(lastarg),arg1))
+      )
+             { hd[e]=I; e=tl[e]=NIL; goto DONE; }
+    setcell(CONS,cons(hd[lastarg],arg2),tl[lastarg]);
+    goto DONE;
+
+    case LEX_DOT: /* LEX_DOT p (c:x) => (c:p) : x
+		     LEX_DOT p  []   => []
+		  */
+    GETARG(arg1);
+    upleft;
+    if((lastarg=reduce(lastarg))==NIL)    /* ### */
+             { hd[e]=I; e=tl[e]=NIL; goto DONE; }
+    setcell(CONS,cons(hd[lastarg],arg1),tl[lastarg]);
+    goto DONE;
+
+    case LEX_CHAR: /* LEX_CHAR c p (c:x) => (c:p) : x
+		      LEX_CHAR c p  x    => []
+		   */
+    GETARG(arg1);
+    GETARG(arg2);
+    upleft;
+    if((lastarg=reduce(lastarg))==NIL||lh(lastarg)!=arg1)    /* ### */
+             { hd[e]=I; e=tl[e]=NIL; goto DONE; }
+    setcell(CONS,cons(arg1,arg2),tl[lastarg]);
+    goto DONE;
+
+    case LEX_SEQ:  /* LEX_SEQ f g p x => [], if f p x = []
+				      => g q y, otherwise
+					 where
+					 (q,y) = f p x
+		   */
+    GETARG(arg1);
+    GETARG(arg2);
+    GETARG(arg3);
+    upleft;
+    hold=ap2(arg1,arg3,lastarg);
+    lastarg=NIL; /* anti-dragging measure */
+    if((hold=reduce(hold))==NIL)     /* ### */
+      { hd[e]=I; e=tl[e]; goto DONE; }
+    hd[e]=ap(arg2,hd[hold]); tl[e]=tl[hold];
+    DOWNLEFT;
+    DOWNLEFT;
+    goto NEXTREDEX;
+
+    case LEX_OR: /* LEX_OR f g p x => g p x, if f p x = []
+				   => f p x, otherwise
+		 */
+    GETARG(arg1);
+    GETARG(arg2);
+    GETARG(arg3);
+    upleft;
+    hold=ap2(arg1,arg3,lastarg);
+    if((hold=reduce(hold))==NIL)        /* ### */
+      { hd[e]=ap(arg2,arg3); DOWNLEFT; DOWNLEFT; goto NEXTREDEX; }
+    hd[e]=I; e=tl[e]=hold;
+    goto DONE;
+
+    case LEX_RCONTEXT: /* LEX_RC f g p x => [], if f p x = []
+					 => [], if g q y = []
+					 => f p x, otherwise  <-*
+			                    where
+			                    (q,y) = f p x
+
+			 (*) special case g=0 means test for y=[]
+		       */
+    GETARG(arg1);
+    GETARG(arg2);
+    GETARG(arg3);
+    upleft;
+    hold=ap2(arg1,arg3,lastarg);
+    lastarg=NIL; /* anti-dragging measure */
+    if((hold=reduce(hold))==NIL     /* ### */
+       || (arg2?(reduce(ap2(arg2,hd[hold],tl[hold]))==NIL)   /* ### */
+	      :(tl[hold]=reduce(tl[hold]))!=NIL ))
+      { hd[e]=I; e=tl[e]; goto DONE; }
+    hd[e]=I; e=tl[e]=hold;
+    goto DONE;
+
+    case LEX_STAR: /* LEX_STAR f p x => p : x, if f p x = []
+				     => LEX_STAR f q y, otherwise
+					where
+					(q,y) = f p x
+		   */
+    GETARG(arg1);
+    GETARG(arg2);
+    upleft;
+    hold=ap2(arg1,arg2,lastarg);
+    while((hold=reduce(hold))!=NIL)   /* ### */
+         arg2=hd[hold],lastarg=tl[hold],hold=ap2(arg1,arg2,lastarg);
+    tag[e]=CONS; hd[e]=arg2;
+    goto DONE;
+
+    case LEX_OPT: /* LEX_OPT f p x => p : x, if f p x = []
+				   => f p x, otherwise
+		   */
+    GETARG(arg1);
+    GETARG(arg2);
+    upleft;
+    hold=ap2(arg1,arg2,lastarg);
+    if((hold=reduce(hold))==NIL)   /* ### */
+      { tag[e]=CONS; hd[e]=arg2; goto DONE; }
+    hd[e]=I; e=tl[e]=hold;
+    goto DONE;
+
+/*  case NUMBER:   /* constructor of arity 1
+    UPLEFT;  /* cannot occur free
+    goto DONE; */ /* UNUSED*/
+
+/*  case CONSTRUCTOR:
+    for(;;){upleft; }  /* reapply to args until DONE */
+
+    default: /* non combinator */
+    cycles--; /* oops! */
+    if(abnormal(e)) /* silly recursion */
+      { fprintf(stderr,"\nBLACK HOLE\n");
+        outstats();
+        exit(1); }
+
+    switch(tag[e])
+    { case STRCONS: e=pn_val(e);  /* private name */
+		    /*if(e==UNDEF||e==FREE)
+		      fprintf(stderr,
+		      "\nimpossible event in reduce - undefined pname\n"),
+		      exit(1);
+	            /* redundant test - remove when sure */
+		    goto NEXTREDEX;
+      case DATAPAIR: /* datapair(oldn,0)(fileinfo(filename,0))=>BOTTOM */
+                     /* kludge for trapping inherited undefined name without
+                        current alias - see code in load_defs */
+                     upleft;
+                     fprintf(stderr,
+                     "\nUNDEFINED NAME (specified as \"%s\" in %s)\n",
+		                     (char *)hd[hd[e]],(char *)hd[lastarg]);
+                     outstats();
+                     exit(1);
+      case ID: if(id_val(e)==UNDEF||id_val(e)==FREE)
+                 { fprintf(stderr,"\nUNDEFINED NAME - %s\n",get_id(e));
+                   outstats();
+                   exit(1); }
+	       /* setcell(AP,I,id_val(e));  /* overwrites error-info */
+	       e=id_val(e);  /* could be eager in value */
+	       goto NEXTREDEX;
+      default: fprintf(stderr,"\nimpossible tag (%d) in reduce\n",tag[e]);
+	       exit(1);
+      case CONSTRUCTOR: for(;;){upleft; } /* reapply to args until DONE */
+      case STARTREADVALS: 
+		/* readvals(0,t) file => READVALS (t:file) streamptr */
+		{ char *fil;
+		  upleft;
+		  lastarg=reduce(lastarg);  /* ### */
+		  if(lastarg==OFFSIDE) /* special case, represents stdin */
+		    { if(stdinuse&&stdinuse!='+')
+                        { tag[e]=AP; hd[e]=I; e=tl[e]=NIL; goto DONE; }
+		      stdinuse='+';
+		      hold=cons(tl[hd[e]],0),lastarg=(word)stdin; }
+		  else
+		    hold=cons(tl[hd[e]],lastarg),
+                    lastarg=(word)fopen(fil=getstring(lastarg,"readvals"),"r");
+                  if((FILE *)lastarg==NULL)  /* cannot open file for reading  */
+                    /* { hd[e]=I; e=tl[e]=NIL; goto DONE; } */
+                    { fprintf(stderr,"\nreadvals, cannot open: \"%s\"\n",fil);
+	              outstats(); exit(1); } 
+                  hd[e]=ap(READVALS,hold); }
+                  DOWNLEFT;
+		  DOWNLEFT;
+                  goto L_READVALS;
+      case ATOM: /* for(;;){upleft; } */
+		 /* as above if there are constructors with tag ATOM
+		    and +ve arity.  Since there are none we could test
+		    for missing combinators at this point. Thus
+		 /*if(!abnormal(s))
+		    fprintf(stderr,"\nreduce: unknown combinator "),
+		    out(stderr,e), putc('\n',stderr),exit(1); */
+      case INT:
+      case UNICODE:
+      case DOUBLE:
+      case CONS:; /* all fall thru to DONE */
+    }
+
+  }  /* end of decode switch  */
+
+  DONE:  /* sub task completed -- s is either BACKSTOP or a tailpointer */
+
+  if(s==BACKSTOP)
+    { /* whole expression now in hnf */
+#ifdef DEBUG
+      if(debug&02)printf("result= "),out(stdout,e),putchar('\n');
+      rdepth--;
+#endif
+      return(e);   /* end of reduction */
+      /* outchar(hd[e]);
+         e=tl[e];
+         goto NEXTREDEX;
+      /* above shows how to incorporate printing into m/c */
+    }
+
+  /* otherwise deal with return from subtask */
+  UPRIGHT;
+  if(tag[e]==AP)
+    { /* we have just reduced argn of strict operator -- so now
+         we must reduce arg(n-1) */
+      DOWNLEFT;
+      DOWNRIGHT; /* there is a faster way to do this - see TRY */
+      goto NEXTREDEX;
+    }
+
+    /* only possible if mktlptr marks the cell rather than the field */
+/*  if(e==BACKSTOP)
+      fprintf(stderr,"\nprogram error: BLACK HOLE2\n"),
+      outstats(),
+      exit(1); */
+
+  /* we are through reducing args of strict operator */
+  /* we can merge the following switch with the main one, if desired,
+     - in this case use the alternate definitions of READY and RESTORE
+     and replace the following switch by
+  /* e=READY(e); goto OPDECODE; */
+
+#ifdef DEBUG
+  if(debug&02){ printf("ready("); out(stdout,e); printf(")\n"); }
+#endif
+  switch(e) /* "ready" switch */
+  {
+/*  case READY(MONOP):/* paradigm for execution of strict monadic operator
+    GETARG(arg1);
+    hd[e]=I; e=tl[e]=do_monop(arg1);
+    goto NEXTREDEX; */
+
+    case READY(I):      /*  I x => x */
+    UPLEFT;
+    e=lastarg;
+    goto NEXTREDEX;
+
+    case READY(SEQ):        /* SEQ a b => b, a~=BOTTOM  */
+    UPLEFT;
+    upleft;
+    hd[e]=I;e=lastarg;
+    goto NEXTREDEX;
+
+    case READY(FORCE):      /*  FORCE x => x, total x */
+    UPLEFT;
+    force(lastarg);
+    hd[e]=I;e=lastarg;
+    goto NEXTREDEX;
+
+    case READY(HD):
+    UPLEFT;
+    if(lastarg==NIL)
+      { fprintf(stderr,"\nATTEMPT TO TAKE hd OF []\n");
+	outstats(); exit(1); }
+    hd[e]=I; e=tl[e]=hd[lastarg];
+    goto NEXTREDEX;
+
+    case READY(TL):
+    UPLEFT;
+    if(lastarg==NIL)
+      { fprintf(stderr,"\nATTEMPT TO TAKE tl OF []\n");
+	outstats(); exit(1); }
+    hd[e]=I; e=tl[e]=tl[lastarg];
+    goto NEXTREDEX;
+
+    case READY(BODY):
+	 /* BODY(k x1 .. xn) => k x1 ... x(n-1)
+            for arbitrary constructor k */
+    UPLEFT;
+    hd[e]=I; e=tl[e]=hd[lastarg];
+    goto NEXTREDEX;
+
+    case READY(LAST):   /* LAST(k x1 .. xn) => xn
+			   for arbitrary constructor k */
+    UPLEFT;
+    hd[e]=I; e=tl[e]=tl[lastarg];
+    goto NEXTREDEX;
+
+    case READY(TAKE):
+    GETARG(arg1);
+    upleft;
+    if(tag[arg1]!=INT)word_error("take");
+    { long long n=get_word(arg1);
+      if(n<=0||(lastarg=reduce(lastarg))==NIL)  /* ### */
+	  { simpl(NIL); goto DONE; }
+      setcell(CONS,hd[lastarg],ap2(TAKE,sto_word(n-1),tl[lastarg])); }
+    goto DONE;
+
+    case READY(FILEMODE): /* FILEMODE string => string'
+			     (see filemode in manual) */
+    UPLEFT;
+    if(!stat(getstring(lastarg,"filemode"),&buf))
+      { mode_t mode=buf.st_mode;
+	word d=S_ISDIR(mode)?'d':'-';
+	word perm= buf.st_uid==geteuid()?(mode&0700)>>6:
+		  buf.st_gid==getegid()?(mode&070)>>3:
+		  mode&07;
+	word r=perm&04?'r':'-',w=perm&02?'w':'-',x=perm&01?'x':'-';
+	setcell(CONS,d,cons(r,cons(w,cons(x,NIL))));
+      }
+    else hd[e]=I,e=tl[e]=NIL;
+    goto DONE;
+
+    case READY(FILESTAT): /* FILESTAT string => ((inode,dev),mtime) */
+    UPLEFT;
+    /* Notes:
+       Non-existent file has conventional ((inode,dev),mtime) of ((0,-1),0)
+       We assume time_t can be stored in int field, this may not port   */
+    if(!stat(getstring(lastarg,"filestat"),&buf))
+        setcell(CONS,cons(sto_word(buf.st_ino),
+                          sto_word(buf.st_dev) ),
+                     sto_word(buf.st_mtime)  );
+    else setcell(CONS,cons(stosmallint(0),
+                           stosmallint(-1) ),
+                      stosmallint(0)  );
+    goto DONE;
+
+    case READY(GETENV):    /* GETENV string => string'
+			      (see man (2) getenv)    */
+    UPLEFT;
+    { char *a = getstring(lastarg,"getenv");
+      unsigned char *p = getenv(a);
+      hold = NIL;
+      if(p){ word i;
+	     unsigned char *q=p, *r=p;
+	     if(UTF8)
+	     { while(*r) /* compress to Latin-1 in situ */
+	       if(*r>127) /* start of multibyte */
+	         if((*r==194||*r==195)&&r[1]>=128&&r[1]<=191) /* Latin-1 */
+	           *q= *r==194?r[1]:r[1]+64, q++, r+=2;
+	         else getenv_error(a),
+		      /* or silently accept errors here? */
+                      *q++=*r++;
+	       else *q++=*r++;
+	       *q='\0';
+	     }
+	     /* convert p to list */
+	     i = strlen(p);
+	     while(i--)hold=cons(p[i],hold);
+	   }
+    }
+    hd[e]=I; e=tl[e]=hold;
+    goto DONE;
+
+    case READY(EXEC):   /* EXEC string
+			   fork off a process to execute string as a
+			   shell command, returning (via pipes) the
+			   triple (stdout,stderr,exit_status)
+			   convention: if fork fails, exit status is -1 */
+    UPLEFT;
+    { word pid=(-1),fd[2],fd_a[2];
+      char *cp=getstring(lastarg,"system");
+      /* pipe(fd) should return 0, -1 means fail */
+      /* fd_a is 2nd pipe, for error messages */
+      if(pipe(fd)==(-1)||pipe(fd_a)==(-1)||(pid=fork()))
+        { /* parent (reader) */
+          FILE *fp,*fp_a;
+          if(pid!= -1)
+            close(fd[1]),
+            close(fd_a[1]),
+            fp=(FILE *)fdopen(fd[0],"r"),
+            fp_a=(FILE *)fdopen(fd_a[0],"r");
+          if(pid== -1||!fp||!fp_a)
+	    setcell(CONS,NIL,cons(piperrmess(pid),sto_word(-1))); else
+          setcell(CONS,ap(READ,fp),cons(ap(READ,fp_a),ap(WAIT,pid)));
+        }
+      else { /* child (writer) */
+             word in;
+             static char *shell="/bin/sh";
+             dup2(fd[1],1); /* so pipe replaces stdout */
+             dup2(fd_a[1],2); /* 2nd pipe replaces stderr */
+             close(fd[1]);
+             close(fd[0]);
+             close(fd_a[1]);
+             close(fd_a[0]);
+	     fclose(stdin);  /* anti side-effect measure */
+             execl(shell,shell,"-c",cp,(char *)0);
+           }
+    }
+    goto DONE;
+
+    case READY(NUMVAL):    /* NUMVAL numeral => number */
+    UPLEFT;
+    { word x=lastarg;
+      word base=10;
+      while(x!=NIL)
+           hd[x]=reduce(hd[x]),        /* ### */
+           x=tl[x]=reduce(tl[x]);  /* ### */
+      while(lastarg!=NIL&&isspace(hd[lastarg]))lastarg=tl[lastarg];
+      x=lastarg;
+      if(x!=NIL&&hd[x]=='-')x=tl[x];
+      if(hd[x]=='0'&&tl[x]!=NIL)
+      switch(tolower(hd[tl[x]]))
+        { case 'o':
+              base=8;
+              x=tl[tl[x]];
+              while(x!=NIL&&isodigit(hd[x]))x=tl[x];
+              break;
+          case 'x':
+              base=16;
+              x=tl[tl[x]];
+              while(x!=NIL&&isxdigit(hd[x]))x=tl[x];
+              break;
+          default: goto L;
+        }
+      else L: while(x!=NIL&&isdigit(hd[x]))x=tl[x];
+      if(x==NIL)
+        hd[e]=I,e=tl[e]=strtobig(lastarg,base);
+      else { char *p=linebuf;
+             double d; char junk=0;
+             x=lastarg;
+             while(x!=NIL&&p-linebuf<BUFSIZE-1) *p++ = hd[x], x=tl[x];
+             *p++ ='\0';
+             if(p-linebuf>60||sscanf(linebuf,"%lf%c",&d,&junk)!=1||junk)
+             { fprintf(stderr,"\nbad arg for numval: \"%s\"\n",linebuf);
+               outstats();
+               exit(1); }
+             else hd[e]=I,e=tl[e]=sto_dbl(d); }
+      goto DONE; }
+
+    case READY(STARTREAD): /* STARTREAD filename => READ streamptr */
+    UPLEFT;
+    { char *fil;
+      lastarg = (word)fopen(fil=getstring(lastarg,"read"),"r");
+      if((FILE *)lastarg==NULL)  /* cannot open file for reading  */
+        /* { hd[e]=I; e=tl[e]=NIL; goto DONE; }
+	     /* could just return empty contents */
+        { fprintf(stderr,"\nread, cannot open: \"%s\"\n",fil);
+	  outstats(); exit(1); } 
+      hd[e]=READ;
+      DOWNLEFT; }
+    goto L_READ;
+
+    case READY(STARTREADBIN): /* STARTREADBIN filename => READBIN streamptr */
+    UPLEFT;
+    { char *fil;
+      lastarg = (word)fopen(fil=getstring(lastarg,"readb"),"r");
+      if((FILE *)lastarg==NULL)  /* cannot open file for reading  */
+        /* { hd[e]=I; e=tl[e]=NIL; goto DONE; }
+	     /* could just return empty contents */
+        { fprintf(stderr,"\nreadb, cannot open: \"%s\"\n",fil);
+	  outstats(); exit(1); } 
+      hd[e]=READBIN;
+      DOWNLEFT; }
+    goto L_READBIN;
+
+    case READY(TRY):   /* TRY FAIL y => y
+			  TRY other y => other  */
+    GETARG(arg1);
+    UPLEFT;
+    if(arg1==FAIL)
+      { hd[e]=I; e=lastarg; goto NEXTREDEX; }
+    if(S<=(hold=head(arg1))&&hold<=ERROR)
+      /* function - other than unsaturated constructor */
+      goto DONE;/* nb! else may take premature decision(interacts with MOD1)*/
+    hd[e]=I;
+    e=tl[e]=arg1;
+    goto NEXTREDEX;
+
+    case READY(COND):      /* COND True => K
+			      COND False => KI  */
+    UPLEFT;
+    hd[e]=I;
+    if(lastarg==True)
+      { e=tl[e]=K; goto L_K; }
+    else { e=tl[e]=KI; goto L_KI; }
+    /* goto OPDECODE;  /* to speed up we have set extra labels */
+
+    /* alternative rules     /*     COND True x => K x
+                                    COND False x => I    */
+
+    case READY(APPEND):    /* APPEND NIL y => y
+			      APPEND (a:x) y => a:APPEND x y  */
+    GETARG(arg1);
+    upleft;
+    if(arg1==NIL)
+      { hd[e]=I,e=lastarg; goto NEXTREDEX; }
+    setcell(CONS,hd[arg1],ap2(APPEND,tl[arg1],lastarg));
+    goto DONE;
+
+    case READY(AND):  /* AND True => I
+			 AND False => K False */
+    UPLEFT;
+    if(lastarg==True){ e=I; goto L_I; }
+    else { hd[e]=K,DOWNLEFT; goto L_K; }
+
+    case READY(OR):   /* OR True => K True
+			 OR False => I  */
+    UPLEFT;
+    if(lastarg==True){ hd[e]=K; DOWNLEFT; goto L_K; }
+    else { e=I; goto L_I; }
+
+    /* alternative rules     ??   /*    AND True y => y
+                                        AND False y => False
+                                        OR True y => True
+                                        OR False y => y    */
+
+    case READY(NOT):            /*    NOT True => False
+                                      NOT False => True    */
+    UPLEFT;
+    hd[e]=I; e=tl[e]=lastarg==True?False:True;
+    goto DONE;
+
+    case READY(NEG):         /*    NEG x => -x, if x is a number */
+    UPLEFT;
+    if(tag[lastarg]==INT)simpl(bignegate(lastarg));
+    else setdbl(e,-get_dbl(lastarg));
+    goto DONE;
+
+    case READY(CODE):  /*  miranda char to int type-conversion  */
+    UPLEFT;
+    simpl(make(INT,get_char(lastarg),0));
+    goto DONE;
+
+    case READY(DECODE):     /*  int to char type conversion */
+    UPLEFT;
+    if(tag[lastarg]==DOUBLE)word_error("decode");
+    long long val=get_word(lastarg);
+    if(val<0||val>UMAX)
+      { fprintf(stderr,"\nCHARACTER OUT-OF-RANGE decode(%d)\n",val);
+        outstats();
+        exit(1); }
+    hd[e]=I; e=tl[e]=sto_char(val);
+    goto DONE;
+
+    case READY(INTEGER):   /* predicate on numbers */
+    UPLEFT;
+    hd[e]=I; e=tl[e]=tag[lastarg]==INT?True:False;
+    goto NEXTREDEX;
+
+    case READY(SHOWNUM):   /*  SHOWNUM number => numeral */
+    UPLEFT;
+    if(tag[lastarg]==DOUBLE)
+    { double x=get_dbl(lastarg);
+#ifndef RYU
+      sprintf(linebuf,"%.16g",x);
+      char *p=linebuf;
+      while isdigit(*p)p++; /* add .0 to false integer */
+      if(!*p)*p++='.',*p++='0',*p='\0';
+      hd[e]=I; e=tl[e]=str_conv(linebuf); }
+#else
+      d2s_buffered(x,linebuf);
+      arg1=str_conv(linebuf);
+      if(*linebuf=='.')arg1=cons('0',arg1);
+      if(*linebuf=='-'&&linebuf[1]=='.')arg1=cons('-',cons('0',tl[arg1]));
+      hd[e]=I; e=tl[e]=arg1; }
+#endif
+    else simpl(bigtostr(lastarg));
+    goto DONE;
+
+   case READY(SHOWHEX):
+    UPLEFT;
+    if(tag[lastarg]==DOUBLE)
+      { sprintf(linebuf,"%a",get_dbl(lastarg));
+        hd[e]=I; e=tl[e]=str_conv(linebuf); }
+    else simpl(bigtostrx(lastarg));
+    goto DONE;
+
+    case READY(SHOWOCT):
+    UPLEFT;
+    if(tag[lastarg]==DOUBLE)word_error("showoct");
+    else simpl(bigtostr8(lastarg));
+    goto DONE;
+
+    /* paradigm for strict monadic arithmetic fns */
+    case READY(ARCTAN_FN): /* atan */
+    UPLEFT;
+    errno=0; /* to clear */
+    setdbl(e,atan(force_dbl(lastarg)));
+    if(errno)math_error("atan");
+    goto DONE;
+
+    case READY(EXP_FN): /* exp */
+    UPLEFT;
+    errno=0; /* to clear */
+    setdbl(e,exp(force_dbl(lastarg)));
+    if(errno)math_error("exp");
+    goto DONE;
+
+    case READY(ENTIER_FN): /* floor */
+    UPLEFT;
+    if(tag[lastarg]==INT)simpl(lastarg);
+    else simpl(dbltobig(get_dbl(lastarg)));
+    goto DONE;
+
+    case READY(LOG_FN): /* log */
+    UPLEFT;
+    if(tag[lastarg]==INT)setdbl(e,biglog(lastarg));
+    else { errno=0; /* to clear */
+           fa=force_dbl(lastarg);
+           setdbl(e,log(fa));
+           if(errno)math_error("log"); }
+    goto DONE;
+
+    case READY(LOG10_FN): /* log10 */
+    UPLEFT;
+    if(tag[lastarg]==INT)setdbl(e,biglog10(lastarg));
+    else { errno=0; /* to clear */
+           fa=force_dbl(lastarg);
+           setdbl(e,log10(fa));
+           if(errno)math_error("log10"); }
+    goto DONE;
+
+    case READY(SIN_FN): /* sin */
+    UPLEFT;
+    errno=0; /* to clear */
+    setdbl(e,sin(force_dbl(lastarg)));
+    if(errno)math_error("sin");
+    goto DONE;
+
+    case READY(COS_FN): /* cos */
+    UPLEFT;
+    errno=0; /* to clear */
+    setdbl(e,cos(force_dbl(lastarg)));
+    if(errno)math_error("cos");
+    goto DONE;
+
+   case READY(SQRT_FN): /* sqrt */
+    UPLEFT;
+    fa=force_dbl(lastarg);
+    if(fa<0.0)math_error("sqrt");
+    setdbl(e,sqrt(fa));
+    goto DONE;
+
+/*  case READY(DIOP):/* paradigm for execution of strict diadic operator
+    RESTORE(e);  /* do not write modified form of operator back into graph
+    GETARG(arg1);
+    GETARG(arg2);
+    hd[e]=I; e=tl[e]=diop(arg1,arg2);
+    goto NEXTREDEX;  */
+
+/*  case READY(EQUAL): /* UNUSED
+    RESTORE(e);
+    GETARG(arg1);
+    GETARG(arg2);
+    if(isap(arg1)&&hd[arg1]!=NUMBER&&isap(arg2)&&hd[arg2]!=NUMBER)
+      { /* recurse on components
+        hd[e]=ap2(EQUAL,tl[arg1],tl[arg2]);
+        hd[e]=ap3(EQUAL,hd[arg1],hd[arg2],hd[e]);
+        tl[e]=False;
+      }  
+    else { hd[e]=I; e=tl[e]= (eqatom(arg1,arg2)?True:False); }
+    goto NEXTREDEX; */
+
+    case READY(ZIP):  /*  ZIP (a:x) (b:y) => (a,b) : ZIP x y
+			  ZIP x y => []  */
+    RESTORE(e);
+    GETARG(arg1);
+    GETARG(arg2);
+    if(arg1==NIL||arg2==NIL)
+     { hd[e]=I; e=tl[e]=NIL; goto DONE; }
+    setcell(CONS,cons(hd[arg1],hd[arg2]),ap2(ZIP,tl[arg1],tl[arg2]));
+    goto DONE;
+
+    case READY(EQ):       /*    EQ x x => True
+                                EQ x y => False
+                          see definition of function "compare" above  */
+    RESTORE(e);
+    GETARG(arg1);
+    UPLEFT;
+    hd[e]=I; e=tl[e]=compare(arg1,lastarg)?False:True;  /* ### */
+    goto DONE;
+
+    case READY(NEQ):      /*    NEQ x x => False
+                                NEQ x y => True
+                          see definition of function "compare" above  */
+    RESTORE(e);
+    GETARG(arg1);
+    UPLEFT;
+    hd[e]=I; e=tl[e]=compare(arg1,lastarg)?True:False;  /* ### */
+    goto DONE;
+
+    case READY(GR):
+    RESTORE(e);
+    GETARG(arg1);
+    UPLEFT;
+    hd[e]=I; e=tl[e]=compare(arg1,lastarg)>0?True:False;  /* ### */
+    goto DONE;
+
+    case READY(GRE):
+    RESTORE(e);
+    GETARG(arg1);
+    UPLEFT;
+    hd[e]=I; e=tl[e]=compare(arg1,lastarg)>=0?True:False;  /* ### */
+    goto DONE;
+
+    case READY(PLUS):
+    RESTORE(e);
+    GETARG(arg1);
+    UPLEFT;
+    if(tag[arg1]==DOUBLE)
+      setdbl(e,get_dbl(arg1)+force_dbl(lastarg)); else
+    if(tag[lastarg]==DOUBLE)
+      setdbl(e,bigtodbl(arg1)+get_dbl(lastarg));
+    else simpl(bigplus(arg1,lastarg));
+    goto DONE;
+
+    case READY(MINUS):
+    RESTORE(e);
+    GETARG(arg1);
+    UPLEFT;
+    if(tag[arg1]==DOUBLE)
+      setdbl(e,get_dbl(arg1)-force_dbl(lastarg)); else
+    if(tag[lastarg]==DOUBLE)
+      setdbl(e,bigtodbl(arg1)-get_dbl(lastarg));
+    else simpl(bigsub(arg1,lastarg));
+    goto DONE;
+
+    case READY(TIMES):
+    RESTORE(e);
+    GETARG(arg1);
+    UPLEFT;
+    if(tag[arg1]==DOUBLE)
+      setdbl(e,get_dbl(arg1)*force_dbl(lastarg)); else
+    if(tag[lastarg]==DOUBLE)
+      setdbl(e,bigtodbl(arg1)*get_dbl(lastarg));
+    else simpl(bigtimes(arg1,lastarg));
+    goto DONE;
+
+    case READY(INTDIV):
+    RESTORE(e);
+    GETARG(arg1);
+    UPLEFT;
+    if(tag[arg1]==DOUBLE||tag[lastarg]==DOUBLE)word_error("div");
+    if(bigzero(lastarg))div_error();  /* build into bigmod ? */
+    simpl(bigdiv(arg1,lastarg));
+    goto DONE;
+
+    case READY(FDIV):
+    RESTORE(e);
+    GETARG(arg1);
+    UPLEFT;
+    /* experiment, suppressed
+    if(tag[lastarg]==INT&&tag[arg1]==INT&&!bigzero(lastarg))
+      { extern int b_rem;
+	int d = bigdiv(arg1,lastarg);
+	if(bigzero(b_rem)){ simpl(d); goto DONE; }
+      } /* makes a/b integer if a, b integers dividing exactly */
+    fa=force_dbl(arg1);
+    fb=force_dbl(lastarg);
+    if(fb==0.0)div_error();
+    setdbl(e,fa/fb);
+    goto DONE;
+
+    case READY(MOD):
+    RESTORE(e);
+    GETARG(arg1);
+    UPLEFT;
+    if(tag[arg1]==DOUBLE||tag[lastarg]==DOUBLE)word_error("mod");
+    if(bigzero(lastarg))div_error();  /* build into bigmod ? */
+    simpl(bigmod(arg1,lastarg));
+    goto DONE;
+
+    case READY(POWER):
+    RESTORE(e);
+    GETARG(arg1);
+    UPLEFT;
+    if(tag[lastarg]==DOUBLE)
+      { fa=force_dbl(arg1);
+        if(fa<0.0)errno=EDOM,math_error("^");
+        fb=get_dbl(lastarg); }else
+    if(tag[arg1]==DOUBLE)
+      fa=get_dbl(arg1),fb=bigtodbl(lastarg); else
+    if(neg(lastarg))
+      fa=bigtodbl(arg1),fb=bigtodbl(lastarg);
+    else { simpl(bigpow(arg1,lastarg));
+	   goto DONE; }
+    errno=0; /* to clear */
+    setdbl(e,pow(fa,fb));
+    if(errno)math_error("power");
+    goto DONE;
+
+    case READY(SHOWSCALED): /* SHOWSCALED precision number => numeral */ 
+    RESTORE(e);
+    GETARG(arg1);
+    UPLEFT;
+    if(tag[arg1]==DOUBLE)
+      word_error("showscaled");
+    arg1=getsmallint(arg1);
+    (void)sprintf(linebuf,"%.*e",arg1,force_dbl(lastarg));
+    hd[e]=I; e=tl[e]=str_conv(linebuf);
+    goto DONE;
+
+    case READY(SHOWFLOAT): /* SHOWFLOAT precision number => numeral */ 
+    RESTORE(e);
+    GETARG(arg1);
+    UPLEFT;
+    if(tag[arg1]==DOUBLE)
+      word_error("showfloat");
+    arg1=getsmallint(arg1);
+    (void)sprintf(linebuf,"%.*f",arg1,force_dbl(lastarg));
+    hd[e]=I; e=tl[e]=str_conv(linebuf);
+    goto DONE;
+
+#define coerce_dbl(x)  tag[x]==DOUBLE?(x):sto_dbl(bigtodbl(x))
+
+    case READY(STEP):  /* STEP i a => GENSEQ (i,NIL) a */
+    RESTORE(e);
+    GETARG(arg1);
+    UPLEFT;
+    hd[e]=ap(GENSEQ,cons(arg1,NIL));
+    goto NEXTREDEX;
+
+    case READY(MERGE): /* MERGE [] y => y
+		          MERGE (a:x) [] => a:x
+			  MERGE (a:x) (b:y) => a:MERGE x (b:y), if a<=b
+					    => b:MERGE (a:x) y, otherwise */
+    RESTORE(e);
+    GETARG(arg1);
+    UPLEFT;
+    if(arg1==NIL)simpl(lastarg); else
+    if(lastarg==NIL)simpl(arg1); else
+    if(compare(hd[arg1]=reduce(hd[arg1]),
+	       hd[lastarg]=reduce(hd[lastarg]))<=0)  /* ### */
+       setcell(CONS,hd[arg1],ap2(MERGE,tl[arg1],lastarg));
+    else setcell(CONS,hd[lastarg],ap2(MERGE,tl[lastarg],arg1));
+    goto DONE;
+
+    case READY(STEPUNTIL):  /* STEPUNTIL i a b => GENSEQ (i,b) a */
+    RESTORE(e);
+    GETARG(arg1);
+    GETARG(arg2);
+    UPLEFT;
+    hd[e]=ap(GENSEQ,cons(arg1,arg2));
+    if(tag[arg1]==INT?poz(arg1):get_dbl(arg1)>=0.0)
+      tag[tl[hd[e]]]=AP; /* hack to record sign of step - see GENSEQ */
+    goto NEXTREDEX;
+
+    case READY(Ush):
+	  /* Ush (k f1...fn) p (k x1...xn)
+		          => "k"++' ':f1 x1 ...++' ':fn xn, p='\0'
+		          => "(k"++' ':f1 x1 ...++' ':fn xn++")", p='\1'
+	     Ush (k f1...fn) p other => FAIL  */
+    RESTORE(e);
+    GETARG(arg1);
+    GETARG(arg2);
+    GETARG(arg3);
+    if(constr_tag(head(arg1))!=constr_tag(head(arg3)))
+      { hd[e]=I;
+	e=tl[e]=FAIL;
+	goto DONE; }  /* result is string, so cannot be more args */
+    if(tag[arg1]==CONSTRUCTOR) /* don't parenthesise atom */
+      { hd[e]=I;
+        if(suppressed(arg1))
+	  e=tl[e]=str_conv("<unprintable>");
+	else e=tl[e]=str_conv(constr_name(arg1));
+	goto DONE; }
+    hold=arg2?cons(')',NIL):NIL;
+    while(tag[arg1]!=CONSTRUCTOR)
+         hold=cons(' ',ap2(APPEND,ap(tl[arg1],tl[arg3]),hold)),
+         arg1=hd[arg1],arg3=hd[arg3];
+    if(suppressed(arg1))
+      { hd[e]=I; e=tl[e]=str_conv("<unprintable>"); goto DONE; }
+    hold=ap2(APPEND,str_conv(constr_name(arg1)),hold);
+    if(arg2)
+      { setcell(CONS,'(',hold); goto DONE; }
+    else { hd[e]=I; e=tl[e]=hold; goto NEXTREDEX; }
+
+    default: fprintf(stderr,"\nimpossible event in reduce ("),
+	     out(stderr,e),fprintf(stderr,")\n"),
+	     exit(1);
+	     return(0); /* proforma only - unreachable */
+  } /* end of "ready" switch */
+
+}  /* end of reduce */
+
+memclass(c,x) /* is char c in list x (may include ranges) */
+{ while(x!=NIL)
+       { if(hd[x]==DOTDOT)
+           { x=tl[x];
+             if(hd[x]<=c&&c<=hd[tl[x]])return(1);
+             x=tl[x]; }
+         else if(c==hd[x])return(1);
+         x=tl[x]; }
+  return(0);
+}
+
+lexfail(x)  /* x is known to be a non-empty string (see LEX_RPT) */
+{ word i=24;
+  fprintf(stderr,"\nLEX FAILS WITH UNRECOGNISED INPUT: \"");
+  while(i--&&x!=NIL&&0<=lh(x)&&lh(x)<=255)
+     fprintf(stderr,"%s",charname(lh(x))),
+     x=tl[x];
+  fprintf(stderr,"%s\"\n",x==NIL?"":"...");
+  outstats();
+  exit(1);
+}
+
+lexstate(x) /* extracts initial state info from list of chars labelled
+               by LEX_COUNT - x is evaluated and known to be non-empty */
+{ x = hd[hd[x]]; /* count field of first char */
+  return(cons(sto_word(x>>8),stosmallint(x&255)));
+}
+
+piperrmess(pid)
+word pid;
+{ return(str_conv(pid== -1?"cannot create process\n":"cannot open pipe\n"));
+}
+
+g_residue(toks2)  /* remainder of token stream from last token examined */
+word toks2;
+{ word toks1 = NIL;
+  if(tag[toks2]!=CONS)
+    { if(tag[toks2]==AP&&hd[toks2]==I&&tl[toks2]==NIL)
+        return(cons(NIL,NIL));
+      return(cons(NIL,toks2)); /*no tokens examined, whole grammar is `error'*/
+      /* fprintf(stderr,"\nimpossible event in g_residue\n"),
+      exit(1); /* grammar fn must have examined >=1 tokens */ }
+  while(tag[tl[toks2]]==CONS)toks1=cons(hd[toks2],toks1),toks2=tl[toks2];
+  if(tl[toks2]==NIL||tag[tl[toks2]]==AP&&hd[tl[toks2]]==I&&tl[tl[toks2]]==NIL)
+    { toks1=cons(hd[toks2],toks1);
+      return(cons(ap(DESTREV,toks1),NIL)); }
+  return(cons(ap(DESTREV,toks1),toks2));
+}
+
+numplus(x,y)
+word x,y;
+{ if(tag[x]==DOUBLE)
+    return(sto_dbl(get_dbl(x)+force_dbl(y)));
+  if(tag[y]==DOUBLE)
+    return(sto_dbl(bigtodbl(x)+get_dbl(y)));
+  return(bigplus(x,y));
+}
+
+fn_error(s)
+char *s;
+{ fprintf(stderr,"\nprogram error: %s\n",s);
+  outstats(); 
+  exit(1); }
+
+getenv_error(char *a)
+{ fprintf(stderr,
+   "program error: getenv(%s): illegal characters in result string\n",a);
+  outstats();
+  exit(1); }
+
+subs_error()
+{ fn_error("subscript out of range");
+}
+
+div_error()
+{ fn_error("attempt to divide by zero");
+}
+/* other arithmetic exceptions signal-trapped by fpe_error - see STEER */
+
+math_error(s)
+char *s;
+{ fprintf(stderr,"\nmath function %serror (%s)\n",
+                 errno==EDOM?"domain ":errno==ERANGE?"range ":"",s);
+  outstats();
+  exit(1);
+}
+
+word_error(s)
+char *s;
+{ fprintf(stderr,
+  "\nprogram error: fractional number where integer expected (%s)\n",s);
+  outstats();
+  exit(1);
+}
+
+char *stdname(c)
+word c;
+{ return c==':' ? "$:-" : c=='-' ? "$-" : "$+"; }
+
+stdin_error(c)
+word c;
+{ if(stdinuse==c)
+        fprintf(stderr,"program error: duplicate use of %s\n",stdname(c));
+  else fprintf(stderr,"program error: simultaneous use of %s and %s\n",
+          stdname(c), stdname(stdinuse));
+  outstats();
+  exit(1);
+}
+
+#ifdef BSDCLOCK
+#include <sys/times.h>
+#include <unistd.h>
+#ifndef CLK_TCK
+#define CLK_TCK sysconf(_SC_CLK_TCK)
+#endif
+#else
+/* this is ANSII C, POSIX */
+#include <time.h>
+clock_t start, end;
+#endif
+
+initclock()
+{ 
+#ifndef BSDCLOCK
+start=clock();
+#endif
+}
+
+out_here(f,h,nl)  /* h is fileinfo(scriptname,line_no) */
+FILE *f;
+word h,nl;
+{ extern word errs;
+  if(tag[h]!=FILEINFO)
+    { fprintf(stderr,"(impossible event in outhere)\n"); return; }
+  fprintf(f,"(line %3d of \"%s\")",tl[h],(char *)hd[h]);
+  if(nl)putc('\n',f); else putc(' ',f);
+  if(compiling&&!errs)errs=h; /* relevant only when called from steer.c */
+} /* `soft' error, set errs rather than errline, so not saved in dump */
+
+outstats()
+{ extern long claims,nogcs;
+  extern word atcount;
+  extern long long cellcount;
+#ifdef BSDCLOCK
+  struct tms buffer;
+#endif
+#ifdef HISTO
+  if(sourcemc)printhisto();
+#endif
+  if(!atcount)return;
+#ifdef BSDCLOCK
+  times(&buffer);
+#else
+  end=clock();
+#endif
+  printf("||");
+  printf("reductions = %lld, cells claimed = %lld, ",
+		cycles,cellcount+claims);
+  printf("no of gc's = %ld, cpu = %0.2f",nogcs,
+#ifdef BSDCLOCK
+	    buffer.tms_utime/(CLK_TCK*1.0));
+#else
+            ((double) (end - start)) / CLOCKS_PER_SEC);
+#endif
+  putchar('\n');
+#ifdef DEBUG
+  printf("||maxr_depth=%d\n",maxrdepth);
+#endif
+}
+
+/* end of MIRANDA REDUCE */
+