RULE* dest = enter_rule( name, m );
RULE* dest = define_rule( source->module, name, m );
RULE* import_rule( RULE* source, module* m, char* name ){    RULE* dest = enter_rule( name, m );    set_rule_body( dest, source->arguments, source->procedure );    set_rule_actions( dest, source->actions );    return dest;}