diff --git a/pkg/expr/mongo.go b/pkg/expr/mongo.go
index 8ff04088d14b4d5072644d2203a0d5a45da2779c..84471ccec2dcc526bd2d588bfd138d028c0202b6 100644
--- a/pkg/expr/mongo.go
+++ b/pkg/expr/mongo.go
@@ -643,6 +643,8 @@ func (c *compiler) PairNode(node *ast.PairNode) interface{} {
 	//c.compile(node.Value)
 }
 
+// notinPatcher проходит по лексемам ast-дерева
+// и объединяет лексемы "not" и "in" в "not in"
 type notinPatcher struct{}
 
 func (t notinPatcher) Visit(node *ast.Node) {
@@ -651,14 +653,14 @@ func (t notinPatcher) Visit(node *ast.Node) {
 		return
 	}
 
-	inNode, ok := nodeNot.Node.(*ast.BinaryNode)
-	if !ok || inNode.Operator != "in" {
+	nodeIn, ok := nodeNot.Node.(*ast.BinaryNode)
+	if !ok || nodeIn.Operator != "in" {
 		return
 	}
 	
 	nodeNot.Operator = ""
 	ast.Patch(node, nodeNot)
 
-	inNode.Operator = "not in"
-	ast.Patch(&nodeNot.Node, inNode)
+	nodeIn.Operator = "not in"
+	ast.Patch(&nodeNot.Node, nodeIn)
 }
\ No newline at end of file