diff --git a/HISTORY b/HISTORY
index 516a07a..2cbeb3e 100755
--- a/HISTORY
+++ b/HISTORY
@@ -1,5 +1,6 @@
 Dec. 28 2015
 Fixed a GC bug
+Fixed a wrong routine evaluation bug
 Improved threshold algorithm for the memory pool
 Polished code
 
diff --git a/core/my_basic.c b/core/my_basic.c
index 1fd2dba..669aceb 100755
--- a/core/my_basic.c
+++ b/core/my_basic.c
@@ -264,8 +264,9 @@ mb_static_assert(_countof(_ERR_DESC) == SE_COUNT);
 
 /* Data type */
 typedef enum _data_e {
-	_DT_NIL = -1,
-	_DT_ANY = 0,
+	_DT_INVALID = -1,
+	_DT_NIL = 0,
+	_DT_KNOWN,
 	_DT_TYPE,
 	_DT_INT,
 	_DT_REAL,
@@ -3533,7 +3534,7 @@ int _create_symbol(mb_interpreter_t* s, _ls_node_t* l, char* sym, _object_t** ob
 			(*obj)->ref = true;
 			*delsym = true;
 		} else {
-			tmp.array = _create_array(sym, _DT_ANY, s);
+			tmp.array = _create_array(sym, _DT_KNOWN, s);
 			memcpy(&tmp.array->type, value, sizeof(tmp.array->type));
 			(*obj)->data.array = tmp.array;
 
@@ -3728,7 +3729,7 @@ _data_e _get_symbol_type(mb_interpreter_t* s, char* sym, _raw_t* value) {
 	_running_context_t* running = 0;
 	_ls_node_t* glbsyminscope = 0;
 	size_t _sl = 0;
-	_data_e en = _DT_ANY;
+	_data_e en = _DT_KNOWN;
 	intptr_t ptr = 0;
 	bool_t mod = false;
 
@@ -4144,10 +4145,10 @@ bool_t _try_get_value(_object_t* obj, mb_value_u* val, _data_e expected) {
 
 	mb_assert(obj && val);
 
-	if(obj->type == _DT_INT && (expected == _DT_ANY || expected == _DT_INT)) {
+	if(obj->type == _DT_INT && (expected == _DT_KNOWN || expected == _DT_INT)) {
 		val->integer = obj->data.integer;
 		result = true;
-	} else if(obj->type == _DT_REAL && (expected == _DT_ANY || expected == _DT_REAL)) {
+	} else if(obj->type == _DT_REAL && (expected == _DT_KNOWN || expected == _DT_REAL)) {
 		val->float_point = obj->data.float_point;
 		result = true;
 	} else if(obj->type == _DT_VAR) {
@@ -4678,7 +4679,7 @@ void _init_array(_array_t* arr) {
 #ifdef MB_SIMPLE_ARRAY
 	elemsize = (int)_get_size_of(arr->type);
 #else /* MB_SIMPLE_ARRAY */
-	elemsize = (int)_get_size_of(_DT_ANY);
+	elemsize = (int)_get_size_of(_DT_KNOWN);
 #endif /* MB_SIMPLE_ARRAY */
 	mb_assert(arr->count > 0);
 	mb_assert(!arr->raw);
@@ -6259,9 +6260,9 @@ int _clone_object(mb_interpreter_t* s, _object_t* obj, _object_t* tgt) {
 		mb_assert(0 && "Not implemented.");
 
 		break;
-	case _DT_TYPE: /* Fall through */
 	case _DT_NIL: /* Fall through */
-	case _DT_ANY: /* Fall through */
+	case _DT_KNOWN: /* Fall through */
+	case _DT_TYPE: /* Fall through */
 	case _DT_INT: /* Fall through */
 	case _DT_REAL: /* Fall through */
 	case _DT_SEP: /* Fall through */
@@ -6361,9 +6362,9 @@ int _dispose_object(_object_t* obj) {
 		}
 
 		break;
-	case _DT_TYPE: /* Fall through */
 	case _DT_NIL: /* Fall through */
-	case _DT_ANY: /* Fall through */
+	case _DT_KNOWN: /* Fall through */
+	case _DT_TYPE: /* Fall through */
 	case _DT_INT: /* Fall through */
 	case _DT_REAL: /* Fall through */
 	case _DT_SEP: /* Fall through */
@@ -10031,7 +10032,7 @@ int _core_let(mb_interpreter_t* s, void** l) {
 	result = _calc_expression(s, &ast, &val);
 
 	if(var) {
-		if(val->type != _DT_ANY) {
+		if(val->type != _DT_KNOWN) {
 			_dispose_object(var->data);
 			var->data->type = val->type;
 #ifdef MB_ENABLE_COLLECTION_LIB
@@ -10048,7 +10049,7 @@ int _core_let(mb_interpreter_t* s, void** l) {
 				var->data->ref = val->ref;
 		}
 	} else if(arr && literally) {
-		if(val->type != _DT_ANY) {
+		if(val->type != _DT_KNOWN) {
 			_unref(&arr_obj->data.array->ref, arr_obj->data.array);
 			arr_obj->type = val->type;
 #ifdef MB_ENABLE_COLLECTION_LIB
@@ -10289,7 +10290,7 @@ _exit:
 
 	*l = ast;
 
-	if(val->type != _DT_ANY)
+	if(val->type != _DT_KNOWN)
 		_destroy_object(val, 0);
 
 	return result;
@@ -10897,7 +10898,7 @@ int _core_def(mb_interpreter_t* s, void** l) {
 	ast = ast->next;
 	routine->func.basic.entry = ast;
 
-	_skip_to(s, &ast, _core_enddef, _DT_NIL);
+	_skip_to(s, &ast, _core_enddef, _DT_INVALID);
 
 	ast = ast->next;