%token A B
%%
start: anbn '\n' { printf("  is in anbn\n");
                   return 0; }
anbn:  A B
     | A anbn B
     ;
%%
#include "lex.yy.c"

main() {
  return yyparse();
}
int yyerror( char *s ) { fprintf( stderr, "%s\n", s); }