assignment
static arith_t assignment(int var, int noeval);
result = assignment(op, noeval);
b = assignment(yylex(), noeval | !a);
result = assignment(yylex(), noeval);
result = assignment(yylex(), 0);
if (l->assignment) {
f_print(fout, " = %s", l->assignment);
last = l->assignment;
elist->assignment = NULL;
elist->assignment = tok.str;
const char *assignment;