diff --git a/src/graph/util/ExpressionUtils.cpp b/src/graph/util/ExpressionUtils.cpp
index 22e7d80c247..77cb5de29a3 100644
--- a/src/graph/util/ExpressionUtils.cpp
+++ b/src/graph/util/ExpressionUtils.cpp
@@ -6,8 +6,10 @@
 #include "graph/util/ExpressionUtils.h"
 
 #include <memory>
+#include <queue>
 
 #include "common/base/ObjectPool.h"
+#include "common/expression/Expression.h"
 #include "common/expression/PropertyExpression.h"
 #include "common/function/AggFunctionManager.h"
 #include "graph/context/QueryContext.h"
@@ -984,5 +986,183 @@ bool ExpressionUtils::isGeoIndexAcceleratedPredicate(const Expression *expr) {
   return false;
 }
 
+bool ExpressionUtils::checkExprDepth(const Expression *expr) {
+  std::queue<const Expression *> exprQueue;
+  exprQueue.emplace(expr);
+  int depth = 0;
+  while (!exprQueue.empty()) {
+    int size = exprQueue.size();
+    while (size > 0) {
+      const Expression *cur = exprQueue.front();
+      exprQueue.pop();
+      switch (cur->kind()) {
+        case Expression::Kind::kConstant:
+        case Expression::Kind::kVar: {
+          break;
+        }
+        case Expression::Kind::kAdd:
+        case Expression::Kind::kMinus:
+        case Expression::Kind::kMultiply:
+        case Expression::Kind::kDivision:
+        case Expression::Kind::kMod: {
+          auto *ariExpr = static_cast<const ArithmeticExpression *>(cur);
+          exprQueue.emplace(ariExpr->left());
+          exprQueue.emplace(ariExpr->right());
+          break;
+        }
+        case Expression::Kind::kIsNull:
+        case Expression::Kind::kIsNotNull:
+        case Expression::Kind::kIsEmpty:
+        case Expression::Kind::kIsNotEmpty:
+        case Expression::Kind::kUnaryPlus:
+        case Expression::Kind::kUnaryNegate:
+        case Expression::Kind::kUnaryNot:
+        case Expression::Kind::kUnaryIncr:
+        case Expression::Kind::kUnaryDecr: {
+          auto *unaExpr = static_cast<const UnaryExpression *>(cur);
+          exprQueue.emplace(unaExpr->operand());
+          break;
+        }
+        case Expression::Kind::kRelEQ:
+        case Expression::Kind::kRelNE:
+        case Expression::Kind::kRelLT:
+        case Expression::Kind::kRelLE:
+        case Expression::Kind::kRelGT:
+        case Expression::Kind::kRelGE:
+        case Expression::Kind::kRelREG:
+        case Expression::Kind::kContains:
+        case Expression::Kind::kNotContains:
+        case Expression::Kind::kStartsWith:
+        case Expression::Kind::kNotStartsWith:
+        case Expression::Kind::kEndsWith:
+        case Expression::Kind::kNotEndsWith:
+        case Expression::Kind::kRelNotIn:
+        case Expression::Kind::kRelIn: {
+          auto *relExpr = static_cast<const RelationalExpression *>(cur);
+          exprQueue.emplace(relExpr->left());
+          exprQueue.emplace(relExpr->right());
+          break;
+        }
+        case Expression::Kind::kList: {
+          auto *listExpr = static_cast<const ListExpression *>(cur);
+          for (auto &item : listExpr->items()) {
+            exprQueue.emplace(item);
+          }
+          break;
+        }
+        case Expression::Kind::kSet: {
+          auto *setExpr = static_cast<const SetExpression *>(cur);
+          for (auto &item : setExpr->items()) {
+            exprQueue.emplace(item);
+          }
+          break;
+        }
+        case Expression::Kind::kMap: {
+          auto *mapExpr = static_cast<const MapExpression *>(cur);
+          for (auto &item : mapExpr->items()) {
+            exprQueue.emplace(item.second);
+          }
+          break;
+        }
+        case Expression::Kind::kCase: {
+          auto *caseExpr = static_cast<const CaseExpression *>(cur);
+          if (caseExpr->hasCondition()) {
+            exprQueue.emplace(caseExpr->condition());
+          }
+          if (caseExpr->hasDefault()) {
+            exprQueue.emplace(caseExpr->defaultResult());
+          }
+          for (auto &whenThen : caseExpr->cases()) {
+            exprQueue.emplace(whenThen.when);
+            exprQueue.emplace(whenThen.then);
+          }
+          break;
+        }
+        case Expression::Kind::kListComprehension: {
+          auto *lcExpr = static_cast<const ListComprehensionExpression *>(cur);
+          exprQueue.emplace(lcExpr->collection());
+          if (lcExpr->hasFilter()) {
+            exprQueue.emplace(lcExpr->filter());
+          }
+          if (lcExpr->hasMapping()) {
+            exprQueue.emplace(lcExpr->mapping());
+          }
+          break;
+        }
+        case Expression::Kind::kPredicate: {
+          auto *predExpr = static_cast<const PredicateExpression *>(cur);
+          exprQueue.emplace(predExpr->collection());
+          if (predExpr->hasFilter()) {
+            exprQueue.emplace(predExpr->filter());
+          }
+          break;
+        }
+        case Expression::Kind::kReduce: {
+          auto *reduceExpr = static_cast<const ReduceExpression *>(cur);
+          exprQueue.emplace(reduceExpr->collection());
+          exprQueue.emplace(reduceExpr->mapping());
+          break;
+        }
+        case Expression::Kind::kLogicalAnd:
+        case Expression::Kind::kLogicalOr:
+        case Expression::Kind::kLogicalXor: {
+          auto *logExpr = static_cast<const LogicalExpression *>(cur);
+          for (auto &op : logExpr->operands()) {
+            exprQueue.emplace(op);
+          }
+          break;
+        }
+        case Expression::Kind::kTypeCasting: {
+          auto *typExpr = static_cast<const TypeCastingExpression *>(cur);
+          exprQueue.emplace(typExpr->operand());
+          break;
+        }
+        case Expression::Kind::kFunctionCall: {
+          auto *funExpr = static_cast<const FunctionCallExpression *>(cur);
+          auto &args = funExpr->args()->args();
+          for (auto iter = args.begin(); iter < args.end(); ++iter) {
+            exprQueue.emplace(*iter);
+          }
+          break;
+        }
+        case Expression::Kind::kTagProperty:
+        case Expression::Kind::kSrcProperty:
+        case Expression::Kind::kEdgeRank:
+        case Expression::Kind::kEdgeDst:
+        case Expression::Kind::kEdgeSrc:
+        case Expression::Kind::kEdgeType:
+        case Expression::Kind::kEdgeProperty:
+        case Expression::Kind::kInputProperty:
+        case Expression::Kind::kSubscript:
+        case Expression::Kind::kAttribute:
+        case Expression::Kind::kLabelAttribute:
+        case Expression::Kind::kVertex:
+        case Expression::Kind::kEdge:
+        case Expression::Kind::kLabel:
+        case Expression::Kind::kVarProperty:
+        case Expression::Kind::kDstProperty:
+        case Expression::Kind::kUUID:
+        case Expression::Kind::kPathBuild:
+        case Expression::Kind::kColumn:
+        case Expression::Kind::kTSPrefix:
+        case Expression::Kind::kTSWildcard:
+        case Expression::Kind::kTSRegexp:
+        case Expression::Kind::kTSFuzzy:
+        case Expression::Kind::kAggregate:
+        case Expression::Kind::kSubscriptRange:
+        case Expression::Kind::kVersionedVar:
+        default:
+          break;
+      }
+      size -= 1;
+    }
+    depth += 1;
+    if (depth > ExpressionUtils::kMaxDepth) {
+      return false;
+    }
+  }
+  return true;
+}  // namespace graph
+
 }  // namespace graph
 }  // namespace nebula
diff --git a/src/graph/util/ExpressionUtils.h b/src/graph/util/ExpressionUtils.h
index 19193cb7a86..f42241f348b 100644
--- a/src/graph/util/ExpressionUtils.h
+++ b/src/graph/util/ExpressionUtils.h
@@ -164,6 +164,10 @@ class ExpressionUtils {
 
   // TODO(jie) Move it to a better place
   static bool isGeoIndexAcceleratedPredicate(const Expression* expr);
+
+  static bool checkExprDepth(const Expression* expr);
+
+  static constexpr int32_t kMaxDepth = 512;
 };
 
 }  // namespace graph
diff --git a/src/parser/parser.yy b/src/parser/parser.yy
index 8c61c1f0e27..c023d520d39 100644
--- a/src/parser/parser.yy
+++ b/src/parser/parser.yy
@@ -223,7 +223,7 @@ static constexpr size_t kCommentLengthLimit = 256;
 %token <strval> STRING VARIABLE LABEL IPV4
 
 %type <strval> name_label unreserved_keyword predicate_name
-%type <expr> expression
+%type <expr> expression expression_internal
 %type <expr> property_expression
 %type <expr> vertex_prop_expression
 %type <expr> edge_prop_expression
@@ -556,6 +556,18 @@ unreserved_keyword
     ;
 
 expression
+    : expression_internal {
+        if(!graph::ExpressionUtils::checkExprDepth($1)){
+            // delete $1;
+            std::ostringstream errStr;
+            errStr << "The above expression's depth exceeds the maximum depth:" << graph::ExpressionUtils::kMaxDepth;
+            throw nebula::GraphParser::syntax_error(@1, errStr.str());
+        }
+        $$ = $1;
+    }
+    ;
+
+expression_internal
     : constant_expression {
         $$ = $1;
     }
@@ -572,7 +584,7 @@ expression
     }
     | MINUS {
         scanner.setUnaryMinus(true);
-    } expression %prec UNARY_MINUS {
+    } expression_internal %prec UNARY_MINUS {
         if (scanner.isIntMin()) {
             $$ = $3;
             scanner.setIsIntMin(false);
@@ -581,98 +593,98 @@ expression
         }
         scanner.setUnaryMinus(false);
     }
-    | PLUS expression %prec UNARY_PLUS {
+    | PLUS expression_internal %prec UNARY_PLUS {
         $$ = UnaryExpression::makePlus(qctx->objPool(), $2);
     }
-    | NOT expression {
+    | NOT expression_internal {
         $$ = UnaryExpression::makeNot(qctx->objPool(), $2);
     }
-    | KW_NOT expression {
+    | KW_NOT expression_internal {
         $$ = UnaryExpression::makeNot(qctx->objPool(), $2);
     }
-    | L_PAREN type_spec R_PAREN expression %prec CASTING {
+    | L_PAREN type_spec R_PAREN expression_internal %prec CASTING {
         $$ = TypeCastingExpression::make(qctx->objPool(), graph::SchemaUtil::propTypeToValueType($2->type), $4);
         delete $2;
     }
-    | expression STAR expression {
+    | expression_internal STAR expression_internal {
         $$ = ArithmeticExpression::makeMultiply(qctx->objPool(), $1, $3);
     }
-    | expression DIV expression {
+    | expression_internal DIV expression_internal {
         $$ = ArithmeticExpression::makeDivision(qctx->objPool(), $1, $3);
     }
-    | expression MOD expression {
+    | expression_internal MOD expression_internal {
         $$ = ArithmeticExpression::makeMod(qctx->objPool(), $1, $3);
     }
-    | expression PLUS expression {
+    | expression_internal PLUS expression_internal {
         $$ = ArithmeticExpression::makeAdd(qctx->objPool(), $1, $3);
     }
-    | expression MINUS expression {
+    | expression_internal MINUS expression_internal {
         $$ = ArithmeticExpression::makeMinus(qctx->objPool(), $1, $3);
     }
-    | expression LT expression {
+    | expression_internal LT expression_internal {
         $$ = RelationalExpression::makeLT(qctx->objPool(), $1, $3);
     }
-    | expression GT expression {
+    | expression_internal GT expression_internal {
         $$ = RelationalExpression::makeGT(qctx->objPool(), $1, $3);
     }
-    | expression LE expression {
+    | expression_internal LE expression_internal {
         $$ = RelationalExpression::makeLE(qctx->objPool(), $1, $3);
     }
-    | expression GE expression {
+    | expression_internal GE expression_internal {
         $$ = RelationalExpression::makeGE(qctx->objPool(), $1, $3);
     }
-    | expression REG expression {
+    | expression_internal REG expression_internal {
         $$ = RelationalExpression::makeREG(qctx->objPool(), $1, $3);
     }
-    | expression KW_IN expression {
+    | expression_internal KW_IN expression_internal {
         $$ = RelationalExpression::makeIn(qctx->objPool(), $1, $3);
     }
-    | expression KW_NOT_IN expression {
+    | expression_internal KW_NOT_IN expression_internal {
         $$ = RelationalExpression::makeNotIn(qctx->objPool(), $1, $3);
     }
-    | expression KW_CONTAINS expression {
+    | expression_internal KW_CONTAINS expression_internal {
         $$ = RelationalExpression::makeContains(qctx->objPool(), $1, $3);
     }
-    | expression KW_NOT_CONTAINS expression {
+    | expression_internal KW_NOT_CONTAINS expression_internal {
         $$ = RelationalExpression::makeNotContains(qctx->objPool(), $1, $3);
     }
-    | expression KW_STARTS_WITH expression {
+    | expression_internal KW_STARTS_WITH expression_internal {
         $$ = RelationalExpression::makeStartsWith(qctx->objPool(), $1, $3);
     }
-    | expression KW_NOT_STARTS_WITH expression {
+    | expression_internal KW_NOT_STARTS_WITH expression_internal {
         $$ = RelationalExpression::makeNotStartsWith(qctx->objPool(), $1, $3);
     }
-    | expression KW_ENDS_WITH expression {
+    | expression_internal KW_ENDS_WITH expression_internal {
         $$ = RelationalExpression::makeEndsWith(qctx->objPool(), $1, $3);
     }
-    | expression KW_NOT_ENDS_WITH expression {
+    | expression_internal KW_NOT_ENDS_WITH expression_internal {
         $$ = RelationalExpression::makeNotEndsWith(qctx->objPool(), $1, $3);
     }
-    | expression KW_IS_NULL {
+    | expression_internal KW_IS_NULL {
         $$ = UnaryExpression::makeIsNull(qctx->objPool(), $1);
     }
-    | expression KW_IS_NOT_NULL {
+    | expression_internal KW_IS_NOT_NULL {
         $$ = UnaryExpression::makeIsNotNull(qctx->objPool(), $1);
     }
-    | expression KW_IS_EMPTY {
+    | expression_internal KW_IS_EMPTY {
         $$ = UnaryExpression::makeIsEmpty(qctx->objPool(), $1);
     }
-    | expression KW_IS_NOT_EMPTY {
+    | expression_internal KW_IS_NOT_EMPTY {
         $$ = UnaryExpression::makeIsNotEmpty(qctx->objPool(), $1);
     }
-    | expression EQ expression {
+    | expression_internal EQ expression_internal {
         $$ = RelationalExpression::makeEQ(qctx->objPool(), $1, $3);
     }
-    | expression NE expression {
+    | expression_internal NE expression_internal {
         $$ = RelationalExpression::makeNE(qctx->objPool(), $1, $3);
     }
-    | expression KW_AND expression {
+    | expression_internal KW_AND expression_internal {
         $$ = LogicalExpression::makeAnd(qctx->objPool(), $1, $3);
     }
-    | expression KW_OR expression {
+    | expression_internal KW_OR expression_internal {
         $$ = LogicalExpression::makeOr(qctx->objPool(), $1, $3);
     }
-    | expression KW_XOR expression {
+    | expression_internal KW_XOR expression_internal {
         $$ = LogicalExpression::makeXor(qctx->objPool(), $1, $3);
     }
     | case_expression {
@@ -712,7 +724,7 @@ constant_expression
     ;
 
 compound_expression
-    : L_PAREN expression R_PAREN {
+    : L_PAREN expression_internal R_PAREN {
         $$ = $2;
     }
     | property_expression {
@@ -751,51 +763,51 @@ property_expression
     ;
 
 subscript_expression
-    : name_label L_BRACKET expression R_BRACKET {
+    : name_label L_BRACKET expression_internal R_BRACKET {
         $$ = SubscriptExpression::make(qctx->objPool(), LabelExpression::make(qctx->objPool(), *$1), $3);
         delete $1;
     }
-    | VARIABLE L_BRACKET expression R_BRACKET {
+    | VARIABLE L_BRACKET expression_internal R_BRACKET {
         $$ = SubscriptExpression::make(qctx->objPool(), VariableExpression::make(qctx->objPool(), *$1), $3);
         delete $1;
     }
-    | compound_expression L_BRACKET expression R_BRACKET {
+    | compound_expression L_BRACKET expression_internal R_BRACKET {
         $$ = SubscriptExpression::make(qctx->objPool(), $1, $3);
     }
     ;
 
 subscript_range_expression
-    : name_label L_BRACKET expression DOT_DOT expression R_BRACKET {
+    : name_label L_BRACKET expression_internal DOT_DOT expression_internal R_BRACKET {
         $$ = SubscriptRangeExpression::make(qctx->objPool(), LabelExpression::make(qctx->objPool(), *$1), $3, $5);
         delete($1);
     }
-    | name_label L_BRACKET DOT_DOT expression R_BRACKET {
+    | name_label L_BRACKET DOT_DOT expression_internal R_BRACKET {
         $$ = SubscriptRangeExpression::make(qctx->objPool(), LabelExpression::make(qctx->objPool(), *$1), nullptr, $4);
         delete($1);
     }
-    | name_label L_BRACKET expression DOT_DOT R_BRACKET {
+    | name_label L_BRACKET expression_internal DOT_DOT R_BRACKET {
         $$ = SubscriptRangeExpression::make(qctx->objPool(), LabelExpression::make(qctx->objPool(), *$1), $3, nullptr);
         delete($1);
     }
-    | VARIABLE L_BRACKET expression DOT_DOT expression R_BRACKET {
+    | VARIABLE L_BRACKET expression_internal DOT_DOT expression_internal R_BRACKET {
         $$ = SubscriptRangeExpression::make(qctx->objPool(), VariableExpression::make(qctx->objPool(), *$1), $3, $5);
         delete($1);
     }
-    | VARIABLE L_BRACKET DOT_DOT expression R_BRACKET {
+    | VARIABLE L_BRACKET DOT_DOT expression_internal R_BRACKET {
         $$ = SubscriptRangeExpression::make(qctx->objPool(), VariableExpression::make(qctx->objPool(), *$1), nullptr, $4);
         delete($1);
     }
-    | VARIABLE L_BRACKET expression DOT_DOT R_BRACKET {
+    | VARIABLE L_BRACKET expression_internal DOT_DOT R_BRACKET {
         $$ = SubscriptRangeExpression::make(qctx->objPool(), VariableExpression::make(qctx->objPool(), *$1), $3, nullptr);
         delete($1);
     }
-    | compound_expression L_BRACKET expression DOT_DOT expression R_BRACKET {
+    | compound_expression L_BRACKET expression_internal DOT_DOT expression_internal R_BRACKET {
         $$ = SubscriptRangeExpression::make(qctx->objPool(), $1, $3, $5);
     }
-    | compound_expression L_BRACKET DOT_DOT expression R_BRACKET {
+    | compound_expression L_BRACKET DOT_DOT expression_internal R_BRACKET {
         $$ = SubscriptRangeExpression::make(qctx->objPool(), $1, nullptr, $4);
     }
-    | compound_expression L_BRACKET expression DOT_DOT R_BRACKET {
+    | compound_expression L_BRACKET expression_internal DOT_DOT R_BRACKET {
         $$ = SubscriptRangeExpression::make(qctx->objPool(), $1, $3, nullptr);
     }
     ;
@@ -832,7 +844,7 @@ generic_case_expression
     ;
 
 conditional_expression
-    : expression QM expression COLON expression {
+    : expression_internal QM expression_internal COLON expression_internal {
         auto cases = CaseList::make(qctx->objPool());
         cases->add($1, $3);
         auto expr = CaseExpression::make(qctx->objPool(), cases, false);
@@ -845,7 +857,7 @@ case_condition
     : %empty {
         $$ = nullptr;
     }
-    | expression {
+    | expression_internal {
         $$ = $1;
     }
     ;
@@ -854,17 +866,17 @@ case_default
     : %empty {
         $$ = nullptr;
     }
-    | KW_ELSE expression {
+    | KW_ELSE expression_internal {
         $$ = $2;
     }
     ;
 
 when_then_list
-    : KW_WHEN expression KW_THEN expression {
+    : KW_WHEN expression_internal KW_THEN expression_internal {
         $$ = CaseList::make(qctx->objPool());
         $$->add($2, $4);
     }
-    | when_then_list KW_WHEN expression KW_THEN expression {
+    | when_then_list KW_WHEN expression_internal KW_THEN expression_internal {
         $1->add($3, $5);
         $$ = $1;
     }
@@ -878,7 +890,7 @@ predicate_name
     ;
 
 predicate_expression
-    : predicate_name L_PAREN expression KW_IN expression KW_WHERE expression R_PAREN {
+    : predicate_name L_PAREN expression_internal KW_IN expression_internal KW_WHERE expression_internal R_PAREN {
         if ($3->kind() != Expression::Kind::kLabel) {
             delete $1;
             throw nebula::GraphParser::syntax_error(@3, "The loop variable must be a label in predicate functions");
@@ -889,7 +901,7 @@ predicate_expression
         $$ = expr;
         delete $1;
     }
-    | KW_EXISTS L_PAREN expression R_PAREN {
+    | KW_EXISTS L_PAREN expression_internal R_PAREN {
         if ($3->kind() != Expression::Kind::kLabelAttribute && $3->kind() != Expression::Kind::kAttribute &&
             $3->kind() != Expression::Kind::kSubscript) {
             throw nebula::GraphParser::syntax_error(@3, "The exists only accept LabelAttribute, Attribute and Subscript");
@@ -899,7 +911,7 @@ predicate_expression
     ;
 
 list_comprehension_expression
-    : L_BRACKET expression KW_IN expression KW_WHERE expression R_BRACKET {
+    : L_BRACKET expression_internal KW_IN expression_internal KW_WHERE expression_internal R_BRACKET {
         if ($2->kind() != Expression::Kind::kLabel) {
             throw nebula::GraphParser::syntax_error(@2, "The loop variable must be a label in list comprehension");
         }
@@ -908,7 +920,7 @@ list_comprehension_expression
         nebula::graph::ParserUtil::rewriteLC(qctx, expr, innerVar);
         $$ = expr;
     }
-    | L_BRACKET expression KW_IN expression PIPE expression R_BRACKET {
+    | L_BRACKET expression_internal KW_IN expression_internal PIPE expression_internal R_BRACKET {
         if ($2->kind() != Expression::Kind::kLabel) {
             throw nebula::GraphParser::syntax_error(@2, "The loop variable must be a label in list comprehension");
         }
@@ -917,7 +929,7 @@ list_comprehension_expression
         nebula::graph::ParserUtil::rewriteLC(qctx, expr, innerVar);
         $$ = expr;
     }
-    | L_BRACKET expression KW_IN expression KW_WHERE expression PIPE expression R_BRACKET {
+    | L_BRACKET expression_internal KW_IN expression_internal KW_WHERE expression_internal PIPE expression_internal R_BRACKET {
         if ($2->kind() != Expression::Kind::kLabel) {
             throw nebula::GraphParser::syntax_error(@2, "The loop variable must be a label in list comprehension");
         }
@@ -929,7 +941,7 @@ list_comprehension_expression
     ;
 
 reduce_expression
-    : KW_REDUCE L_PAREN name_label ASSIGN expression COMMA name_label KW_IN expression PIPE expression R_PAREN {
+    : KW_REDUCE L_PAREN name_label ASSIGN expression_internal COMMA name_label KW_IN expression_internal PIPE expression_internal R_PAREN {
         auto *expr = ReduceExpression::make(qctx->objPool(), *$3, $5, *$7, $9, $11);
         nebula::graph::ParserUtil::rewriteReduce(qctx, expr, *$3, *$7);
         $$ = expr;
@@ -1016,7 +1028,7 @@ function_call_expression
             throw nebula::GraphParser::syntax_error(@1, "Unknown function ");
         }
     }
-    | LABEL L_PAREN KW_DISTINCT expression R_PAREN {
+    | LABEL L_PAREN KW_DISTINCT expression_internal R_PAREN {
         if (AggFunctionManager::find(*$1).ok()) {
             $$ = AggregateExpression::make(qctx->objPool(), *$1, $4, true);
             delete($1);
@@ -1136,13 +1148,13 @@ argument_list
         Expression *arg = EdgeExpression::make(qctx->objPool());
         $$->addArgument(arg);
     }
-    | expression {
+    | expression_internal {
         $$ = ArgumentList::make(qctx->objPool());
         Expression* arg = nullptr;
         arg = $1;
         $$->addArgument(arg);
     }
-    | argument_list COMMA expression {
+    | argument_list COMMA expression_internal {
         $$ = $1;
         Expression* arg = nullptr;
         arg = $3;
@@ -1280,11 +1292,11 @@ opt_expression_list
     ;
 
 expression_list
-    : expression {
+    : expression_internal {
         $$ = ExpressionList::make(qctx->objPool());
         $$->add($1);
     }
-    | expression_list COMMA expression {
+    | expression_list COMMA expression_internal {
         $$ = $1;
         $$->add($3);
     }
@@ -1309,12 +1321,12 @@ opt_map_item_list
     ;
 
 map_item_list
-    : name_label COLON expression {
+    : name_label COLON expression_internal {
         $$ = MapItemList::make(qctx->objPool());
         $$->add(*$1, $3);
         delete $1;
     }
-    | map_item_list COMMA name_label COLON expression {
+    | map_item_list COMMA name_label COLON expression_internal {
         $$ = $1;
         $$->add(*$3, $5);
         delete $3;
diff --git a/src/parser/test/ParserBenchmark.cpp b/src/parser/test/ParserBenchmark.cpp
index b1af6f3dc42..d420f1547d9 100644
--- a/src/parser/test/ParserBenchmark.cpp
+++ b/src/parser/test/ParserBenchmark.cpp
@@ -14,9 +14,7 @@ auto simpleQuery = "USE myspace";
 auto complexQuery =
     "GO 2 STEPS FROM 123456789 OVER myedge "
     "WHERE alias.prop1 + alias.prop2 * alias.prop3 > alias.prop4 AND "
-    "alias.prop5 == alias.prop6 YIELD 1 AS first, 2 AS second";
-
-auto qctx = std::make_unique<nebula::graph::QueryContext>();
+    "alias.prop5 == alias.prop6 YIELD 1+1+1+1+1+1+1+1 AS first, 2 AS second";
 
 size_t SimpleQuery(size_t iters, size_t nrThreads) {
   constexpr size_t ops = 500000UL;
@@ -24,6 +22,7 @@ size_t SimpleQuery(size_t iters, size_t nrThreads) {
   auto parse = [&]() {
     auto n = iters * ops;
     for (auto i = 0UL; i < n; i++) {
+      auto qctx = std::make_unique<nebula::graph::QueryContext>();
       // static thread_local GQLParser parser;
       GQLParser parser(qctx.get());
       auto result = parser.parse(simpleQuery);
@@ -48,6 +47,7 @@ size_t ComplexQuery(size_t iters, size_t nrThreads) {
   auto parse = [&]() {
     auto n = iters * ops;
     for (auto i = 0UL; i < n; i++) {
+      auto qctx = std::make_unique<nebula::graph::QueryContext>();
       // static thread_local GQLParser parser;
       GQLParser parser(qctx.get());
       auto result = parser.parse(complexQuery);
@@ -87,11 +87,13 @@ BENCHMARK_RELATIVE_NAMED_PARAM_MULTI(ComplexQuery, 48_thread, 48)
 int main(int argc, char **argv) {
   gflags::ParseCommandLineFlags(&argc, &argv, true);
   {
+    auto qctx = std::make_unique<nebula::graph::QueryContext>();
     GQLParser parser(qctx.get());
     auto result = parser.parse(simpleQuery);
     CHECK(result.ok()) << result.status();
   }
   {
+    auto qctx = std::make_unique<nebula::graph::QueryContext>();
     GQLParser parser(qctx.get());
     auto result = parser.parse(complexQuery);
     CHECK(result.ok()) << result.status();
diff --git a/tests/tck/features/expression/Depth.feature b/tests/tck/features/expression/Depth.feature
new file mode 100644
index 00000000000..71bf5e3498e
--- /dev/null
+++ b/tests/tck/features/expression/Depth.feature
@@ -0,0 +1,159 @@
+# Copyright (c) 2021 vesoft inc. All rights reserved.
+#
+# This source code is licensed under Apache 2.0 License.
+Feature: Check Expression Depth
+
+  Background:
+    Given a graph with space named "nba"
+
+  Scenario: yield exceeds expression
+    When executing query:
+      """
+      YIELD 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 +
+      1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 +
+      1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 +
+      1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 +
+      1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 +
+      1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 +
+      1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 +
+      1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 +
+      1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 +
+      1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 +
+      1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 +
+      1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 +
+      1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 +
+      1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 +
+      1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 +
+      1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 +
+      1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 +
+      1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 +
+      1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 +
+      1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 +
+      1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 +
+      1 + 1 + 1 + 1 + 1 + 1 + 1 AS result
+      """
+    Then the result should be, in any order:
+      | result |
+      | 488    |
+    When executing query:
+      """
+      YIELD 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 +
+      1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 +
+      1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 +
+      1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 +
+      1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 +
+      1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 +
+      1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 +
+      1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 +
+      1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 +
+      1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 +
+      1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 +
+      1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 +
+      1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 +
+      1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 +
+      1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 +
+      1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 +
+      1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 +
+      1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 +
+      1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 +
+      1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 +
+      1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 +
+      1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 +
+      1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 +
+      1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 +
+      1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 +
+      1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 +
+      1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 +
+      1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 +
+      1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 +
+      1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 +
+      1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 +
+      1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 +
+      1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 +
+      1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 +
+      1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 +
+      1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 +
+      1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 AS result
+      """
+    Then a SyntaxError should be raised at runtime: The above expression's depth exceeds the maximum depth
+    When executing query:
+      """
+      YIELD 1 IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS
+      NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL IS NULL AS result
+      """
+    Then a SyntaxError should be raised at runtime: The above expression's depth exceeds the maximum depth