Question

How do I compile, link and call different YACC grammars using yyparse() in one program?

Answer 1

Use the -p option for each separate yacc grammar generation

 -p prefix             Use prefix instead of yy as the prefix for all external            names produced by yacc.  For X/Open compliance, when the            environment variable _XPG is set, then the -p option will work            as described in the previous sentence.  If the environment            variable _XPG is not set, then the -p option will work as            described below in the -P option.