public static function get_inference_result(Language_variable_collection $langvar_coll, $method = 'closure_addition') { if (is_null(Fuzzy_inference_engine::$engine)) { $class_name = 'Fuzzy_inference_engine_' . $method; require_once $class_name . '.php'; Fuzzy_inference_engine::$engine = new $class_name(); } return Fuzzy_inference_engine::$engine->get_inference_result($langvar_coll); }