makefork
i = makefork(FAMP, i);
left = makefork(FPOU, t);
right = makefork(FPIN, term(NLFLG));
return(makefork(0, makelist(TFIL, left, right)));
r = makefork(0, p);
r = makefork(0,r);
extern struct trenod *makefork();
t = makefork(FPOU, cmd(EOFSYM, MTFLG | NLFLG ));