import Miranda 2.066 from upstream

1 files changed, 656 insertions, 0 deletions

diff --git a/big.c b/big.c
new file mode 100644
index 0000000..05f346b
--- /dev/null
+++ b/big.c
@@ -0,0 +1,656 @@
+/* MIRANDA INTEGER PACKAGE */
+/* package for unbounded precision integers */
+
+/**************************************************************************
+ * 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.              *
+ *                                                                        *
+ * Revised to C11 standard and made 64bit compatible, January 2020        *
+ *------------------------------------------------------------------------*/
+
+#include "data.h"
+#include "lex.h"
+#include "big.h"
+#include <errno.h>
+
+static double logIBASE,log10IBASE;
+word big_one;
+
+static word big_plus(word,word,int);
+static word big_sub(word,word);
+static word len(word);
+static word longdiv(word,word);
+static word ms2d(word);
+static word msd(word);
+static word shift(word,word);
+static word shortdiv(word,word);
+static word stimes(word,word);
+
+void bigsetup()
+{ logIBASE=log((double)IBASE);
+  log10IBASE=log10((double)IBASE);
+  big_one=make(INT,1,0);
+}
+
+int isnat(x)
+word x;
+{ return(tag[x]==INT&&poz(x));
+}
+
+word sto_int(i)  /* store C long long as mira bigint */
+long long i;
+{ word s,x;
+  if(i<0)s=SIGNBIT,i= -i; else s=0;
+  x=make(INT,s|i&MAXDIGIT,0);
+  if(i>>=DIGITWIDTH)
+    { word *p = &rest(x);
+      *p=make(INT,i&MAXDIGIT,0),p= &rest(*p);
+      while(i>>=DIGITWIDTH)
+           *p=make(INT,i&MAXDIGIT,0),p= &rest(*p); }
+  return(x);
+} /* change to long long, DT Oct 2019 */
+
+#define maxval (1ll<<60)
+
+long long get_int(x) /* mira bigint to C long long */
+word x;
+{ long long n=digit0(x);
+  word sign=neg(x);
+  if(!(x=rest(x)))return(sign?-n:n);
+{ word w=DIGITWIDTH;
+  while(x&&w<60)n+=(long long)digit(x)<<w,w+=DIGITWIDTH,x=rest(x);
+  if(x)n=maxval; /* overflow, return large value */
+  return(sign?-n:n);
+}} /* change to long long, DT Oct 2019 */
+
+word bignegate(x)
+word x;
+{ if(bigzero(x))return(x);
+  return(make(INT,hd[x]&SIGNBIT?hd[x]&MAXDIGIT:SIGNBIT|hd[x],tl[x]));
+}
+
+word bigplus(x,y)
+word x,y;
+{ if(poz(x))
+    if(poz(y))return(big_plus(x,y,0));
+    else return(big_sub(x,y));
+  else
+    if(poz(y))return(big_sub(y,x));
+    else return(big_plus(x,y,SIGNBIT)); /* both negative */
+}
+
+word big_plus(x,y,signbit) /* ignore input signs, treat x,y as positive */
+word x,y; int signbit;
+{ word d=digit0(x)+digit0(y);
+  word carry = ((d&IBASE)!=0);
+  word r = make(INT,signbit|d&MAXDIGIT,0); /* result */
+  word *z = &rest(r); /* pointer to rest of result */
+  x = rest(x); y = rest(y);
+  while(x&&y) /* this loop has been unwrapped once, see above */
+       { d = carry+digit(x)+digit(y);
+	 carry = ((d&IBASE)!=0);
+         *z = make(INT,d&MAXDIGIT,0);
+	 x = rest(x); y = rest(y); z = &rest(*z); }
+  if(y)x=y; /* by convention x is the longer one */
+  while(x)
+       { d = carry+digit(x);
+	 carry = ((d&IBASE)!=0);
+         *z = make(INT,d&MAXDIGIT,0);
+	 x = rest(x); z = &rest(*z); }
+  if(carry)*z=make(INT,1,0);
+  return(r);
+}
+
+word bigsub(x,y)
+word x,y;
+{ if(poz(x))
+    if(poz(y))return(big_sub(x,y));
+    else return(big_plus(x,y,0)); /* poz x, negative y */
+  else
+    if(poz(y))return(big_plus(x,y,SIGNBIT)); /* negative x, poz y */
+    else return(big_sub(y,x)); /* both negative */
+}
+
+word big_sub(x,y) /* ignore input signs, treat x,y as positive */
+word x,y;
+{ word d = digit0(x)-digit0(y);
+  word borrow = (d&IBASE)!=0;
+  word r=make(INT,d&MAXDIGIT,0);  /* result */
+  word *z = &rest(r);
+  word *p=NULL; /* pointer to trailing zeros, if any */
+  x = rest(x); y = rest(y);
+  while(x&&y) /* this loop has been unwrapped once, see above */
+       { d = digit(x)-digit(y)-borrow;
+	 borrow = (d&IBASE)!=0;
+	 d = d&MAXDIGIT;
+         *z = make(INT,d,0);
+	 if(d)p=NULL; else if(!p)p=z;
+	 x = rest(x); y = rest(y); z = &rest(*z); }
+  while(y) /* at most one of these two loops will be invoked */
+       { d = -digit(y)-borrow;
+	 borrow = ((d&IBASE)!=0);
+	 d = d&MAXDIGIT;
+         *z = make(INT,d,0);
+	 if(d)p=NULL; else if(!p)p=z;
+	 y = rest(y); z = &rest(*z); }
+  while(x) /* alternative loop */
+       { d = digit(x)-borrow;
+	 borrow = ((d&IBASE)!=0);
+	 d = d&MAXDIGIT;
+         *z = make(INT,d,0);
+	 if(d)p=NULL; else if(!p)p=z;
+	 x = rest(x); z = &rest(*z); }
+  if(borrow) /* result is negative  - take complement and add 1 */
+    { p=NULL;
+      d = (digit(r)^MAXDIGIT) + 1;
+      borrow = ((d&IBASE)!=0);  /* borrow now means `carry' (sorry) */
+      digit(r) = SIGNBIT|d;  /* set sign bit of result */
+      z = &rest(r);
+      while(*z)
+	   { d = (digit(*z)^MAXDIGIT)+borrow;
+             borrow = ((d&IBASE)!=0);
+             digit(*z) = d = d&MAXDIGIT;
+	     if(d)p=NULL; else if(!p)p=z;
+	     z = &rest(*z); }
+    }
+  if(p)*p=0; /* remove redundant (ie trailing) zeros */
+  return(r);
+}
+
+int bigcmp(x,y)  /* returns +ve,0,-ve as x greater than, equal, less than y */
+word x,y;
+{ word d,r,s=neg(x);
+  if(neg(y)!=s)return(s?-1:1);
+  r=digit0(x)-digit0(y);
+  for(;;)
+     { x=rest(x); y=rest(y);
+       if(!x)if(y)return(s?1:-1);
+             else return(s?-r:r);
+       if(!y)return(s?-1:1);
+       d=digit(x)-digit(y);
+       if(d)r=d; }
+}
+
+word bigtimes(x,y) /* naive multiply - quadratic */
+word x,y;
+{ if(len(x)<len(y))
+    { word hold=x; x=y; y=hold; }  /* important optimisation */
+  word r=make(INT,0,0);
+  word d = digit0(y);
+  word s=neg(y);
+  word n=0;
+  if(bigzero(x))return(r);  /* short cut */
+  for(;;)
+     { if(d)r = bigplus(r,shift(n,stimes(x,d)));
+       n++;
+       y = rest(y);
+       if(!y)
+         return(s!=neg(x)?bignegate(r):r);
+       d=digit(y); }
+}
+
+
+word shift(n,x) /* multiply big x by n'th power of IBASE */
+word n,x;
+{ while(n--)x=make(INT,0,x);
+  return(x);
+} /* NB - we assume x non-zero, else unnormalised result */
+
+word stimes(x,n)  /* multiply big x (>=0) by digit n (>0) */
+word x,n;
+{ unsigned d= n*digit0(x);  /* ignore sign of x */
+  word carry=d>>DIGITWIDTH;
+  word r = make(INT,d&MAXDIGIT,0);
+  word *y = &rest(r);
+  while(x=rest(x))
+       d=n*digit(x)+carry,
+       *y=make(INT,d&MAXDIGIT,0),
+       y = &rest(*y),
+       carry=d>>DIGITWIDTH;
+  if(carry)*y=make(INT,carry,0);
+  return(r);
+}
+
+word b_rem;  /* contains remainder from last call to longdiv or shortdiv */
+
+word bigdiv(x,y)  /* may assume y~=0 */
+word x,y;
+{ word s1,s2,q; 
+  /* make x,y positive and remember signs */
+  if(s1=neg(y))y=make(INT,digit0(y),rest(y));
+  if(neg(x))
+    x=make(INT,digit0(x),rest(x)),s2=!s1; 
+  else s2=s1;
+  /* effect: s1 set iff y negative, s2 set iff signs mixed */
+  if(rest(y))q=longdiv(x,y);
+  else q=shortdiv(x,digit(y));
+  if(s2){ if(!bigzero(b_rem))
+	    { x=q;
+	      while((digit(x)+=1)==IBASE) /* add 1 to q in situ */
+                   { digit(x)=0;
+		     if(!rest(x)){ rest(x)=make(INT,1,0); break; }
+		     else x=rest(x);
+		   }
+	    }
+          if(!bigzero(q))digit(q)=SIGNBIT|digit(q);
+	}
+  return(q);
+}
+
+word bigmod(x,y)  /* may assume y~=0 */
+word x,y;
+{ word s1,s2;
+  /* make x,y positive and remember signs */
+  if(s1=neg(y))y=make(INT,digit0(y),rest(y));
+  if(neg(x))
+    x=make(INT,digit0(x),rest(x)),s2=!s1; 
+  else s2=s1;
+  /* effect: s1 set iff y negative, s2 set iff signs mixed */
+  if(rest(y))longdiv(x,y);
+  else shortdiv(x,digit(y));
+  if(s2){ if(!bigzero(b_rem))
+	    b_rem = bigsub(y,b_rem);
+	}
+  return(s1?bignegate(b_rem):b_rem);
+}
+
+/* NB - above have entier based handling of signed cases  (as  Miranda)  in
+   which  remainder  has  sign  of  divisor.   To  get  this:-  if signs of
+   divi(sor/dend) mixed negate quotient  and  if  remainder  non-zero  take
+   complement and add one to magnitude of quotient */
+
+/* for alternative, truncate based handling of signed cases (usual in  C):-
+   magnitudes  invariant  under  change  of  sign,  remainder  has  sign of
+   dividend, quotient negative if signs of divi(sor/dend) mixed */
+
+word shortdiv(x,n) /* divide big x by single digit n returning big quotient
+		 and setting external b_rem as side effect */
+              /* may assume - x>=0,n>0 */
+word x,n;
+{ word d=digit(x),s_rem,q=0;
+  while(x=rest(x))  /* reverse rest(x) into q */
+       q=make(INT,d,q),d=digit(x);  /* leaving most sig. digit in d */
+  { word tmp;
+    x=q; s_rem=d%n; d=d/n;
+    if(d||!q)q=make(INT,d,0); /* put back first digit (if not leading 0) */
+    else q=0;
+    while(x) /* in situ division of q by n AND destructive reversal */
+         d=s_rem*IBASE+digit(x),digit(x)=d/n,s_rem=d%n,
+	 tmp=x,x=rest(x),rest(tmp)=q,q=tmp;
+  }
+  b_rem=make(INT,s_rem,0);
+  return(q);
+}
+
+word longdiv(x,y)  /* divide big x by big y returning quotient, leaving
+		 remainder in extern variable b_rem */
+              /* may assume - x>=0,y>0 */
+word x,y;
+{ word n,q,ly,y1,scale;
+  if(bigcmp(x,y)<0){ b_rem=x; return(make(INT,0,0)); }
+  y1=msd(y);
+  if((scale=IBASE/(y1+1))>1) /* rescale if necessary */
+    x=stimes(x,scale),y=stimes(y,scale),y1=msd(y);
+  n=q=0;ly=len(y);
+  while(bigcmp(x,y=make(INT,0,y))>=0)n++;
+  y=rest(y);  /* want largest y not exceeding x */
+  ly += n;
+  for(;;)
+     { word d,lx=len(x);
+       if(lx<ly)d=0; else
+       if(lx==ly)
+         if(bigcmp(x,y)>=0)x=bigsub(x,y),d=1;
+	 else d=0;
+       else{ d=ms2d(x)/y1;
+	     if(d>MAXDIGIT)d=MAXDIGIT;
+	     if((d -= 2)>0)x=bigsub(x,stimes(y,d));
+	     else d=0;
+             if(bigcmp(x,y)>=0)
+	       { x=bigsub(x,y),d++;
+                 if(bigcmp(x,y)>=0)
+		   x=bigsub(x,y),d++; }
+	   }
+       q = make(INT,d,q);
+       if(n-- ==0)
+	 { b_rem = scale==1?x:shortdiv(x,scale); return(q); }
+       ly-- ; y = rest(y); }
+} /* see Bird & Wadler p82 for explanation */
+
+word len(x) /* no of digits in big x */
+word x;
+{ word n=1;
+  while(x=rest(x))n++;
+  return(n);
+}
+
+word msd(x) /* most significant digit of big x */
+word x;
+{ while(rest(x))x=rest(x);
+  return(digit(x)); /* sign? */
+}
+
+word ms2d(x) /* most significant 2 digits of big x (len>=2) */
+word x;
+{ word d=digit(x);
+  x=rest(x);
+  while(rest(x))d=digit(x),x=rest(x);
+  return(digit(x)*IBASE+d);
+}
+
+word bigpow(x,y)  /* assumes y poz */
+word x,y;
+{ word d,r=make(INT,1,0);
+  while(rest(y))  /* this loop has been unwrapped once, see below */
+       { word i=DIGITWIDTH;
+	 d=digit(y);
+	 while(i--)
+	      { if(d&1)r=bigtimes(r,x); 
+		x = bigtimes(x,x);
+		d >>= 1; }
+	 y=rest(y);
+       }
+  d=digit(y);
+  if(d&1)r=bigtimes(r,x); 
+  while(d>>=1)
+       { x = bigtimes(x,x);
+         if(d&1)r=bigtimes(r,x); }
+  return(r);
+}
+
+double bigtodbl(x)
+word x;
+{ word s=neg(x);
+  double b=1.0, r=(double)digit0(x);
+  x = rest(x);
+  while(x)b=b*IBASE,r=r+b*digit(x),x=rest(x);
+  if(s)return(-r);
+  return(r);
+} /* small end first */
+/* note: can return oo, -oo
+   but is used without surrounding sto_/set)dbl() only in compare() */
+
+/* not currently used
+long double bigtoldbl(x)
+word x;
+{ int s=neg(x);
+  long double b=1.0L, r=digit0(x);
+  x = rest(x);
+  while(x)b=b*IBASE,r=r+b*digit(x),x=rest(x);
+/*printf("bigtoldbl returns %Le\n",s?-r:r); /* DEBUG
+  if(s)return(-r);
+  return(r);
+} /* not compatible with std=c90, lib fns eg sqrtl broken */
+
+word dbltobig(x)  /* entier */
+double x;
+{ word s= (x<0);
+  word r=make(INT,0,0);
+  word *p = &r;
+  double y= floor(x);
+/*if(fabs(y-x+1.0)<1e-9)y += 1.0; /* trick due to Peter Bartke, see note */
+  for(y=fabs(y);;)
+     { double n = fmod(y,(double)IBASE);
+       digit(*p) = (word)n;
+       y = (y-n)/(double)IBASE; 
+       if(y>0.0)rest(*p)=make(INT,0,0),p=&rest(*p);
+       else break;
+     }
+  if(s)digit(r)=SIGNBIT|digit(r);
+  return(r);
+}
+/* produces junk in low order digits if x exceeds range in which integer
+   can be held without error as a double -- NO, see next comment */
+/* hugs, ghci, mira produce same integer for floor/entier hugenum, has 2^971
+   as factor so the low order bits are NOT JUNK -- 9.1.12 */
+
+/* note on suppressed fix:
+   choice of 1e9 arbitrary, chosen to prevent eg entier(100*0.29) = 28
+   but has undesirable effects, causing eg entier 1.9999999999 = 2
+   underlying problem is that computable floor on true Reals is _|_ at
+   the exact integers.  There are inherent deficiences in 64 bit fp,
+   no point in trying to mask this */
+
+double biglog(x)  /* logarithm of big x */
+word x;
+{ word n=0;
+  double r=digit(x);
+  if(neg(x)||bigzero(x))errno=EDOM,math_error("log");
+  while(x=rest(x))n++,r=digit(x)+r/IBASE;
+  return(log(r)+n*logIBASE);
+}
+
+double biglog10(x)  /* logarithm of big x */
+word x;
+{ word n=0;
+  double r=digit(x);
+  if(neg(x)||bigzero(x))errno=EDOM,math_error("log10");
+  while(x=rest(x))n++,r=digit(x)+r/IBASE;
+  return(log10(r)+n*log10IBASE);
+}
+
+word bigscan(p)  /* read a big number (in decimal) */
+            /* NB does NOT check for malformed number, assumes already done */
+char *p;    /* p is a pointer to a null terminated string of digits */
+{ word s=0,r=make(INT,0,0);
+  if(*p=='-')s=1,p++; /* optional leading `-' (for NUMVAL) */
+  while(*p)
+       { word d= *p-'0',f=10;
+	 p++;
+	 while(*p&&f<PTEN)d=10*d+*p-'0',f=10*f,p++;
+	 /* rest of loop does r=f*r+d; (in situ) */
+	 d= f*digit(r)+d;
+       { word carry=d>>DIGITWIDTH;
+	 word *x = &rest(r);
+	 digit(r)=d&MAXDIGIT;
+	 while(*x)
+	      d=f*digit(*x)+carry,
+	      digit(*x)=d&MAXDIGIT,
+	      carry=d>>DIGITWIDTH,
+	      x = &rest(*x);
+	 if(carry)*x=make(INT,carry,0);
+       }}
+/*if(*p=='e')
+    { int s=bigscan(p+1);
+      r = bigtimes(r,bigpow(make(INT,10,0),s); } */
+  if(s&&!bigzero(r))digit(r)=digit(r)|SIGNBIT;
+  return(r);
+}
+/* code to handle (unsigned) exponent commented out */
+
+word bigxscan(p,q)  /* read unsigned hex number in '\0'-terminated string p to q */
+               /* assumes redundant leading zeros removed */
+char *p, *q;
+{ word r; /* will hold result */
+  word *x = &r;
+  if(*p=='0'&&!p[1])return make(INT,0,0);
+  while(q>p)
+       { unsigned long long hold;
+         q = q-p<15 ? p : q-15; /* read upto 15 hex digits from small end */
+         sscanf(q,"%llx",&hold);
+         *q = '\0';
+         word count=4; /* 15 hex digits => 4 bignum digits */
+         while(count-- && !(hold==0 && q==p))
+              *x = make(INT,hold&MAXDIGIT,0),
+              hold >>= DIGITWIDTH,
+              x = &rest(*x);
+       }
+  return r;
+}
+
+word bigoscan(p,q)  /* read unsigned octal number in '\0'-terminated string p to q */
+               /* assumes redundant leading zeros removed */
+char *p, *q;
+{ word r; /* will hold result */
+  word *x = &r;
+  while(q>p)
+       { unsigned hold;
+         q = q-p<5 ? p : q-5; /* read (upto) 5 octal digits from small end */
+         sscanf(q,"%o",&hold);
+         *q = '\0';
+         *x = make(INT,hold,0),
+         x = &rest(*x);
+       }
+  return r;
+}
+
+word digitval(c)
+char c;
+{ return isdigit(c)?c-'0':
+         isupper(c)?10+c-'A':
+         10+c-'a'; }
+
+word strtobig(z,base) /* numeral (as Miranda string) to big number */
+                      /* does NOT check for malformed numeral, assumes
+	                 done and that z fully evaluated */
+word z; int base;
+{ word s=0,r=make(INT,0,0),PBASE=PTEN;
+  if(base==16)PBASE=PSIXTEEN; else
+  if(base==8)PBASE=PEIGHT;
+  if(z!=NIL&&hd[z]=='-')s=1,z=tl[z]; /* optional leading `-' (for NUMVAL) */
+  if(base!=10)z=tl[tl[z]]; /* remove "0x" or "0o" */
+  while(z!=NIL)
+       { word d=digitval(hd[z]),f=base;
+         z=tl[z];
+         while(z!=NIL&&f<PBASE)d=base*d+digitval(hd[z]),f=base*f,z=tl[z];
+         /* rest of loop does r=f*r+d; (in situ) */
+         d= f*digit(r)+d;
+       { word carry=d>>DIGITWIDTH;
+         word *x = &rest(r);
+         digit(r)=d&MAXDIGIT;
+         while(*x)
+              d=f*digit(*x)+carry,
+              digit(*x)=d&MAXDIGIT,
+              carry=d>>DIGITWIDTH,
+              x = &rest(*x);
+         if(carry)*x=make(INT,carry,0);
+       }}
+  if(s&&!bigzero(r))digit(r)=digit(r)|SIGNBIT;
+  return(r);
+}
+
+extern char *dicp;
+
+word bigtostr(x) /* number to decimal string (as Miranda list) */
+word x;
+{ word x1,sign,s=NIL;
+#ifdef DEBUG
+  extern int debug;
+  if(debug&04)  /* print octally */
+    { word d=digit0(x);
+      sign=neg(x);
+      for(;;)
+	   { word i=OCTW;
+	     while(i--||d)s=cons('0'+(d&07),s),d >>= 3;
+             x=rest(x);
+             if(x)s=cons(' ',s),d=digit(x);
+	     else return(sign?cons('-',s):s); }
+    }
+#endif
+  if(rest(x)==0)
+    { extern char *dicp;
+      sprintf(dicp,"%ld",getsmallint(x));
+      return(str_conv(dicp)); }
+  sign=neg(x);
+  x1=make(INT,digit0(x),0); /* reverse x into x1 */
+  while(x=rest(x))x1=make(INT,digit(x),x1);
+  x=x1;
+  for(;;)
+     { /* in situ division of (reversed order) x by PTEN */
+       word d=digit(x),rem=d%PTEN;
+       d=d/PTEN; x1=rest(x);
+       if(d)digit(x)=d;
+       else x=x1; /* remove leading zero from result */
+       while(x1)
+            d=rem*IBASE+digit(x1),
+            digit(x1)=d/PTEN,
+            rem=d%PTEN,
+            x1=rest(x1);
+       /* end of in situ division (also uses x1 as temporary) */
+       if(x)
+         { word i=TENW;
+	   while(i--)s=cons('0'+rem%10,s),rem=rem/10; }
+       else
+	 { while(rem)s=cons('0'+rem%10,s),rem=rem/10;
+           return(sign?cons('-',s):s); }
+     }
+}
+
+word bigtostrx(x) /* integer to hexadecimal string (as Miranda list) */
+word x;
+{ word r=NIL, s=neg(x);
+  while(x)
+       { word count=4; /* 60 bits => 20 octal digits => 4 bignum digits */
+         unsigned long long factor=1;
+         unsigned long long hold=0;
+         while(count-- && x) /* calculate value of (upto) 4 bignum digits */
+              hold=hold+factor*digit0(x),
+              /* printf("::%llx\n",hold), /* DEBUG */
+              factor<<=15,
+              x=rest(x);
+         sprintf(dicp,"%.15llx",hold); /* 15 hex digits = 60 bits */
+         /* printf(":::%s\n",dicp); /* DEBUG */
+         char *q=dicp+15;
+         while(--q>=dicp)r = cons(*q,r);
+       }
+  while(digit(r)=='0'&&rest(r)!=NIL)r=rest(r); /* remove redundant leading 0's */
+  r = cons('0',cons('x',r));
+  if(s)r = cons('-',r);
+  return(r);
+}
+
+word bigtostr8(x) /* integer to octal string (as Miranda list) */
+word x;
+{ word r=NIL, s=neg(x);
+  while(x)
+       { char *q = dicp+5;
+         sprintf(dicp,"%.5lo",digit0(x));
+         while(--q>=dicp)r = cons(*q,r);
+         x = rest(x); }
+  while(digit(r)=='0'&&rest(r)!=NIL)r=rest(r); /* remove redundant leading 0's */
+  r = cons('0',cons('o',r));
+  if(s)r = cons('-',r);
+  return(r);
+}
+
+#ifdef DEBUG
+wff(x) /* check for well-formation of integer */
+word x;
+{ word y=x;
+  if(tag[x]!=INT)printf("BAD TAG %d\n",tag[x]);
+  if(neg(x)&&!digit0(x)&&!rest(x))printf("NEGATIVE ZERO!\n");
+  if(digit0(x)&(~MAXDIGIT))printf("OVERSIZED DIGIT!\n");
+  while(x=rest(x))
+       if(tag[x]!=INT)printf("BAD INTERNAL TAG %d\n",tag[x]); else
+       if(digit(x)&(~MAXDIGIT))
+	 printf("OVERSIZED DIGIT!\n"); else
+       if(!digit(x)&&!rest(x))
+	 printf("TRAILING ZERO!\n");
+  return(y);
+}
+
+normalise(x)  /* remove trailing zeros */
+word x;
+{ if(rest(x))rest(x)=norm1(rest(x));
+  return(wff(x));
+}
+
+norm1(x)
+word x;
+{ if(rest(x))rest(x)=norm1(rest(x));
+  return(!digit(x)&&!rest(x)?0:x);
+}
+
+#endif
+
+/* stall(s)
+char *s;
+{ fprintf(stderr,"big integer %s not yet implemented\n",s);
+  exit(0);
+}
+
+#define destrev(x,y,z)  while(x)z=x,x=rest(x),rest(z)=y,y=z;
+/* destructively reverse x into y using z as temp */
+
+/* END OF MIRANDA INTEGER PACKAGE */
+