diff --git a/_config.yml b/_config.yml
index 3397c9a..f2ede7c 100644
--- a/_config.yml
+++ b/_config.yml
@@ -1 +1 @@
-theme: jekyll-theme-architect
\ No newline at end of file
+theme: jekyll-theme-architect
diff --git a/core/my_basic.c b/core/my_basic.c
index c98bbc0..0ab9248 100755
--- a/core/my_basic.c
+++ b/core/my_basic.c
@@ -1343,6 +1343,10 @@ static int mb_uu_substr(const char* ch, int begin, int count, char** o);
 
 /** Expression processing */
 
+#ifndef _ONCOND
+#	define _ONCOND(__s, __o, __v) do { ((void)(__s)); ((void)(__o)); ((void)(__v)); } while(0)
+#endif /* _ONCOND */
+
 static bool_t _is_operator(mb_func_t op);
 static bool_t _is_flow(mb_func_t op);
 static bool_t _is_unary(mb_func_t op);
@@ -15110,6 +15114,7 @@ static int _core_not(mb_interpreter_t* s, void** l) {
 
 		mb_check(mb_attempt_func_end(s, l));
 	}
+	_ONCOND(s, 0, &arg);
 
 	switch(arg.type) {
 	case MB_DT_NIL:
@@ -15535,6 +15540,7 @@ static int _core_if(mb_interpreter_t* s, void** l) {
 _elseif:
 	_MAKE_NIL(val);
 	result = _calc_expression(s, &ast, &val);
+	_ONCOND(s, val, 0);
 	if(result != MB_FUNC_OK)
 		goto _exit;
 
@@ -15819,6 +15825,7 @@ _loop_begin:
 	ast = loop_begin_node;
 
 	result = _calc_expression(s, &ast, &loop_cond_ptr);
+	_ONCOND(s, loop_cond_ptr, 0);
 	if(result != MB_FUNC_OK)
 		goto _exit;
 
@@ -15932,6 +15939,7 @@ _loop_begin:
 	ast = ast->next;
 
 	result = _calc_expression(s, &ast, &loop_cond_ptr);
+	_ONCOND(s, loop_cond_ptr, 0);
 	if(result != MB_FUNC_OK)
 		goto _exit;
 
diff --git a/shell/main.c b/shell/main.c
index 0158b4d..208cd3f 100755
--- a/shell/main.c
+++ b/shell/main.c
@@ -97,7 +97,7 @@ extern "C" {
 
 #define _REALLOC_INC_STEP 16
 
-#define _NO_END(s) ((s) == MB_FUNC_OK || (s) == MB_FUNC_SUSPEND || (s) == MB_FUNC_WARNING || (s) == MB_FUNC_ERR || (s) == MB_FUNC_END)
+#define _NOT_FINISHED(s) ((s) == MB_FUNC_OK || (s) == MB_FUNC_SUSPEND || (s) == MB_FUNC_WARNING || (s) == MB_FUNC_ERR || (s) == MB_FUNC_END)
 
 static struct mb_interpreter_t* bas = 0;
 
@@ -993,9 +993,9 @@ static void _show_help(void) {
 	_printf("Options:\n");
 	_printf("  -h         - Show help information\n");
 #if _USE_MEM_POOL
-	_printf("  -p n       - Set memory pool threashold size, n is size in bytes\n");
+	_printf("  -p n       - Set memory pool threashold, n is size in bytes\n");
 #endif /* _USE_MEM_POOL */
-	_printf("  -f \"dirs\"  - Set importing directories, separated with \";\" for more than one\n");
+	_printf("  -f \"dirs\"  - Set importing directories, separated with \";\" with more than one\n");
 	_printf("\n");
 	_printf("Interactive commands:\n");
 	_printf("  HELP  - View help information\n");
@@ -1585,7 +1585,7 @@ int main(int argc, char* argv[]) {
 		_show_tip();
 		do {
 			status = _do_line();
-		} while(_NO_END(status));
+		} while(_NOT_FINISHED(status));
 	}
 
 	return 0;