@x
@*Intro. This program finds the prime implicants of a given
self-dual threshold function. It outputs them in a format that
can be used as input to Mathematica to find ``optimum'' weights.
@y
@*Intro. This program finds the prime implicants of a given
self-dual threshold function. It outputs them in a format that
can be used as input to the {\mc LP} program.
@z
@x
int going; /* have we printed any constraints yet? */
@y
int going; /* have we printed any constraints yet? */
int impl[1000][100]; /* linear constraints to be transposed */
@z
@x
  register int j,l,n,t;
  @<Read the command line@>;
  @<Print the first line of output@>;
@y
  register int j,l,n,t,m=0;
  @<Read the command line@>;
@z
@x
@ @<Print a linear constraint for the current prime implicant@>=
if (!going) going=1;
else printf("\n  && ");
for (j=0;j<n;j++) printf("%c%c",x[j]?'+':'-','a'+j);
printf(">=1");

@ @<Print the last line of output@>=
printf("},\n ");
for (j=0;j<n;j++) printf("%c%c",j?',':'{','a'+j);
printf("}]\n");
@y
@ @<Print a linear constraint for the current prime implicant@>=
for (j=0;j<n;j++) impl[m][j]=(x[j]?+1:-1);
m++;

@ @<Print the last line of output@>=
for (l=0;l<m;l++) printf(" 1");
printf("\n");
for (j=0;j<n;j++) {
  printf("1");
  for (l=0;l<m;l++) printf(" %d",impl[l][j]);
  printf("\n");
}
@z