# include <stdio.h>
extern char inf1[],outf[80];
extern short **mat[],pinv[],**spm,*spv,prime,dim,cp[],exp,opmats;
FILE *fopen(),*ip,*ips,*op;

matact(inter) char inter;
{ short substeps,subexp,subdp,*commno,*commvec,**commer,**commkeep,
  intexp,ncommer,ncomm,i,j,k,l,m,n,*ptr,*ptre,*ptr2,incr;
  char subfile[4],infc[80];
  commer=mat[3*exp+1]; commkeep=mat[3*exp+2]; commno=spm[1]; commvec=spm[2];
  if (inter)
  { if ((ip=fopen(inf1,"r"))==0)
    { fprintf(stderr,"Cannot open %s\n",inf1); return(-1);}
    strcpy(subfile,"axa");
    incr=exp;
  }
  else { incr=0; intexp=exp; strcpy(subfile,"xa");}

/* The following loop is executed once only if inter = 0 (Checking relations for
   P). If inter=1, it is executed once for each Sylow intersection Q in the
   file inf1 (=gpname.sc?).
*/
  while (1)
  { if (inter)
    { fscanf(ip,"%hd",&intexp);
      if (intexp==0)
      { subfile[0]++; subfile[2]='a'; continue;}
      if (intexp== -1) break;
      if (intexp>=exp)
      { fprintf(stderr,"Sylow intersection too large.\n"); return(-1);}
      seeknln(); seeknln();
/* Read generators of Q and compute matrices */
      for (i=1;i<=intexp;i++)
      { fscanf(ip,"%hd",&l); l /=2; ptr=ptre=cp;
        for (j=1;j<=l;j++)
        { fscanf(ip,"%hd%hd",&m,&n);
          if (m<=0 || m>exp || n<=0 || n>prime)
          { fprintf(stderr,"Invalid data in %s.\n",inf1); return(-1);}
          ptre+=n; while (++ptr<=ptre) *ptr=m; ptr=ptre;
        }
        *cp=ptre-cp;
        prod(cp,mat[exp+i]);
      }
      if (opmats)
      { strcpy(outf,inf1); strncat(outf,subfile,1);  strcat(outf,"mats");
        op=fopen(outf,"w");
        fprintf(op,"%4d%4d%4d\n",prime,dim,intexp);
        for (i=1;i<=intexp;i++) printmat(mat[exp+i]);
        fclose(op);
      }
/* Skip rest of data for this Q */
      k=3+intexp*(intexp+1)/2;
      for (i=1;i<=k;i++) seeknln();
    }
      
/* The following loop (restart) is executed once for each file of inf1xa,
   inf1xb,... of subgroups of Q.
*/
restart:
    strcpy(infc,inf1); strcat(infc,subfile);
    if ((ips=fopen(infc,"r"))==0)
/* No more files of subgroups. */
    { if (inter==0) break;
      subfile[0]++; subfile[2]='a'; continue;
    }
    fscanf(ips,"%hd%hd",&subexp,&substeps);
    if (subexp<=0 || subexp>intexp)
    { fprintf(stderr,"Invalid data in %s.\n",infc); return(-1);}
    printf("File %s:  substeps=%d.\n",infc,substeps);
    for (i=1;i<=subexp;i++)
    { if (subexp==intexp) { *cp=1; cp[1]=i+incr;}
      else
      { fscanf(ips,"%hd",&l); l /=2; ptr=ptre=cp;
        for (j=1;j<=l;j++)
        { fscanf(ips,"%hd%hd",&m,&n);
          if (m<=0 || m>intexp || n<=0 || n>prime)
          { fprintf(stderr,"Invalid data in %s.\n",infc); return(-1);}
          ptre+=n; while (++ptr<=ptre) *ptr=m+incr; ptr=ptre;
        }
        *cp=ptre-cp;
      }
      prod(cp,mat[2*exp+i]);
    }
  
    for (i=1;i<=dim;i++)
    { for (j=1;j<=dim;j++) commer[i][j]=0; commer[i][i]=1;}
    ncommer=dim;
    for (subdp=1;subdp<=substeps;subdp++)
    { ncomm=0; for (i=1;i<=dim;i++) commno[i]=0;
      for (i=1;i<=ncommer;i++) for (j=1;j<=subexp;j++)
      { k=comm(commer[i],commvec,mat[2*exp+j]);
        if (subdp==substeps)
        { if (k!=0)
          { fprintf(stderr,
                    "Error: subdp,i,j,  inf=%d,%d,%d,%s\n",subdp,i,j,infc);
            subfile[1+inter]++; fclose(ips); goto restart;
          }
        }
        else
        { ptr=commvec+dim+1;
          for (k=dim;k>=1;k--) if ((l= *(--ptr))!=0)
          { n=pinv[l];
            for (m=k;m>=1;m--) {*ptr*=n; *(ptr--)%=prime;}
            if ((n=commno[k])!=0)
            { ptr=commvec+k; ptr2=commkeep[commno[k]]+k;
              while (ptr>commvec)
              { *(ptr)-= *ptr2;
                if (*ptr<0) *ptr+=prime;
                ptr--; ptr2--;
              }
              ptr=commvec+k;
            }
            else
            { ncomm++; commno[k]=ncomm;
              ptr=commkeep[ncomm]; ptre=ptr+dim; ptr2=commvec;
              while (++ptr<=ptre) *ptr= *(++ptr2);
              break;
            }
          }
        }
      }
  
      if (subdp<substeps)
      { fscanf(ips,"%hd",&i);
        if (i!=0)
        { subexp=i;
          if (subexp<=0 || subexp>intexp)
          { fprintf(stderr,"Invalid data in %s.\n",infc); return(-1);}
          for (i=1;i<=subexp;i++)
          { if (subexp==intexp) {*cp=1; cp[1]=i+incr;}
            else
            { fscanf(ips,"%hd",&l); l /=2; ptr=ptre=cp;
              for (j=1;j<=l;j++)
              { fscanf(ips,"%hd%hd",&m,&n);
                if (m<=0 || m>intexp || n<=0 || n>prime)
                { fprintf(stderr,"Invalid data in %s.\n",infc); return(-1);}
                ptre+=n; while (++ptr<=ptre) *ptr=m+incr; ptr=ptre;
              }
              *cp=ptre-cp;
            }
            prod(cp,mat[2*exp+i]);
          }
        }
        for (i=1;i<=ncomm;i++)
        { ptr=commer[i]; ptre=ptr+dim; ptr2=commkeep[i];
          while (++ptr<=ptre) *ptr= *(++ptr2);
        }
        ncommer=ncomm;
      }
    }
    printf("File %s is ok.\n",infc);
    fclose(ips); subfile[1+inter]++;
    goto restart;
  }
}

seeknln() {while (getc(ip)!='\n');}
