/*M	Groebner basis over rational functions over the rationals	input: a list of polymials over rational functions over	       the rationalsM*/#include <_pol4.h>main(){  single anz,met,r,r1,r2;  rfunc  F;  pol    P;  list   VL,VL1,VL2,PL,PL1;  init(F,P,VL,VL1,VL2,PL,PL1);  PL    = _0;  GBRHO = 0;/* list of variables for the rational function field */  printf("\n Enter the variable list for the rational function field\n");  printf(" (e.g. in the form \"a b c #\") : ");  VL2 = getvl();  r2  = llength(VL2);/* list of variables occuring in the polynomials */  printf("\n Enter the variable list for the polynomials\n");  printf(" (e.g. in the form \"x y z #\") : ");  VL1 = getvl();  r1  = llength(VL1);/* term order */  printf("\n The following term orders are possible:\n");  printf("          - lexicographical                      ( EVORD = 1 ),\n");  printf("          - graduated lexicographical            ( EVORD = 2 ),\n");  printf("          - total degree ordering\n");  printf("            (Buchberger's total degree ordering) ( EVORD = 3 ),\n");  printf("          - lexicographical with inverse\n");  printf("            exponent vector                      ( EVORD = 4 ).\n");  printf(" EVORD = ");  EVORD = getsi();/* list of polynomials over rational functions over the rationals */  printf("\n Enter a list of polynomials over rational functions over the rationals\n in the form\n");  printf("         { p1 ... pm }\n");  printf(" where each polynomial pi ends with a '#'.\n ");  PL = getdiprfrl(r1,r2,VL1,VL2);/* computation of the Groebner basis */  printf("\n normal / recursive method ?  1 / 0 : ");  met = getsi();  if ( met == 1 )  PL1 = diprfrgb(r1,r2,PL);  /*  <---- normal Groebner basis algorithm ---- */  else  PL1 = diprfrgbr(r1,r2,PL);            /*  <---- recursive Groebner basis algorithm ---- *//* output */  printf("\n Groebner basis :");  putdiprfrl(r1,r2,PL1,VL1,VL2);}