From c0528ca2381b82ae1cfbe04e1dfb09e427a8288d Mon Sep 17 00:00:00 2001
From: Kevin Gibbons <bakkot@gmail.com>
Date: Mon, 3 Jul 2023 13:37:04 -0700
Subject: [PATCH] fix "there exists"/"such that" not followed by a var name

---
 src/lint/rules/variable-use-def.ts |  2 +-
 test/lint-variable-use-def.js      | 16 ++++++++++++++++
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/src/lint/rules/variable-use-def.ts b/src/lint/rules/variable-use-def.ts
index 77c4d7af..b2addcc9 100644
--- a/src/lint/rules/variable-use-def.ts
+++ b/src/lint/rules/variable-use-def.ts
@@ -289,7 +289,7 @@ function walkAlgorithm(
         if (
           prev.name === 'text' &&
           // prettier-ignore
-          /\b(?:for any |for some |there exists |there is |there does not exist )(\w+ )*$/.test(prev.contents)
+          /\b(?:for any |for some |there exists |there is |there does not exist )((?!of |in )(\w+ ))*$/.test(prev.contents)
         ) {
           scope.declare(varName, part);
           declaredThisLine.add(part);
diff --git a/test/lint-variable-use-def.js b/test/lint-variable-use-def.js
index 16f8b0c2..18007e90 100644
--- a/test/lint-variable-use-def.js
+++ b/test/lint-variable-use-def.js
@@ -115,6 +115,22 @@ describe('variables are declared and used appropriately', () => {
       );
     });
 
+    it('"there exists a value in _x_ with a property" does not declare _x_"', async () => {
+      await assertLint(
+        positioned`
+          <emu-alg>
+            1. If there exists an integer in ${M}_x_ greater than 0, return *true*.
+            1. Return *false*.
+          </emu-alg>
+        `,
+        {
+          ruleId: 'use-before-def',
+          nodeType: 'emu-alg',
+          message: 'could not find a preceding declaration for "x"',
+        }
+      );
+    });
+
     it('variables in a loop header other than the loop variable must be declared', async () => {
       await assertLint(
         positioned`