diff --git a/.istanbul.yml b/.istanbul.yml
deleted file mode 100644
index a5269c0..0000000
--- a/.istanbul.yml
+++ /dev/null
@@ -1,2 +0,0 @@
-instrumentation:
-  excludes: ['lib/parser.js']
\ No newline at end of file
diff --git a/lib/texutil.js b/lib/texutil.js
index 4e4d16b..596f2df 100644
--- a/lib/texutil.js
+++ b/lib/texutil.js
@@ -696,9 +696,9 @@ module.exports.fun_ar1 = arr2set([
     '\\vec',
     '\\widehat',
     '\\widetilde',
-    '\\xcancel',
-    '\\xleftarrow',
-    '\\xrightarrow'
+    '\\xcancel'
+    // '\\xleftarrow', // moved to fun_ar1nb
+    // '\\xrightarrow' // moved to fun_ar1nb
 ]);
 
 module.exports.fun_mhchem = arr2set([
@@ -718,7 +718,9 @@ module.exports.fun_ar1nb = arr2set([
     '\\mathbb',
     '\\mathbf',
     '\\mathrm',
-    '\\underbrace'
+    '\\underbrace',
+    '\\xleftarrow',
+    '\\xrightarrow'
 ]);
 
 module.exports.fun_ar1opt = arr2set([
@@ -756,11 +758,11 @@ module.exports.declh_function = arr2set([
     '\\bf'
 ]);
 
-module.exports.left_function = arr2set([ '\\left' ]);
-module.exports.right_function = arr2set([ '\\right' ]);
-module.exports.hline_function = arr2set([ '\\hline' ]);
-module.exports.definecolor_function = arr2set([ '\\definecolor' ]);
-module.exports.color_function = arr2set([ '\\color', '\\pagecolor' ]);
+module.exports.left_function = arr2set(['\\left']);
+module.exports.right_function = arr2set(['\\right']);
+module.exports.hline_function = arr2set(['\\hline']);
+module.exports.definecolor_function = arr2set(['\\definecolor']);
+module.exports.color_function = arr2set(['\\color', '\\pagecolor']);
 
 // ------------------------------------------------------
 // Package dependencies for various allowed commands.
diff --git a/package.json b/package.json
index 854fde0..80d93de 100644
--- a/package.json
+++ b/package.json
@@ -1,11 +1,11 @@
 {
   "name": "mathoid-texvcjs",
-  "version": "0.3.8",
-  "description": "A TeX/LaTeX validator for mediawiki.",
+  "version": "0.3.9",
+  "description": "A TeX/LaTeX validator for MediaWiki.",
   "main": "lib/index.js",
   "scripts": {
     "build": "node -e 'require(\"./lib/build-parser\")'",
-    "cover": "nyc --reporter=lcov _mocha",
+    "cover": "nyc --reporter=lcov --exclude lib/parser.js_mocha ",
     "lint": "eslint --max-warnings 0 --ext .js .",
     "test": "node -e 'require(\"./lib/build-parser\")' && npm run lint && mocha",
     "report-coverage": "cat ./coverage/lcov.info | coveralls"
@@ -26,14 +26,13 @@
     "url": "https://phabricator.wikimedia.org/project/profile/1771/"
   },
   "dependencies": {
-    "commander": "~4.1.1"
+    "commander": "~5.0.0"
   },
   "devDependencies": {
     "coveralls": "^3.0.11",
     "nyc": "^15.0.0",
     "eslint-config-wikimedia": "^0.15.0",
-    "istanbul": "^0.4.5",
-    "mocha": "~7.0.1",
+    "mocha": "~7.1.1",
     "mocha-lcov-reporter": "^1.3.0",
     "pegjs": "~0.10.0"
   },
diff --git a/test/all.js b/test/all.js
index b2918b5..01584bd 100644
--- a/test/all.js
+++ b/test/all.js
@@ -299,7 +299,7 @@ describe('Comprehensive test cases', function () {
                 '\\overline{A}\\overrightarrow{A}\\pmod{A}\\sqrt{A}' +
                 '\\textbf{A}\\textit{A}\\textrm{A}\\textsf{A}\\texttt{A}' +
                 '\\tilde{A}\\underline{A}\\vec{A}\\widehat{A}\\widetilde{A}' +
-                '\\xcancel{A}\\xleftarrow{A}\\xrightarrow{A}',
+                '\\xcancel{A}',
             output:
                 '{\\acute {A}}{\\bar {A}}{\\bcancel {A}}{\\bmod {A}}' +
                 '{\\boldsymbol {A}}{\\breve {A}}{\\cancel {A}}{\\check {A}}' +
@@ -313,8 +313,7 @@ describe('Comprehensive test cases', function () {
                 '{\\overrightarrow {A}}{\\pmod {A}}{\\sqrt {A}}' +
                 '{\\textbf {A}}{\\textit {A}}{\\textrm {A}}{\\textsf {A}}' +
                 '{\\texttt {A}}{\\tilde {A}}{\\underline {A}}{\\vec {A}}' +
-                '{\\widehat {A}}{\\widetilde {A}}{\\xcancel {A}}' +
-                '{\\xleftarrow {A}}{\\xrightarrow {A}}',
+                '{\\widehat {A}}{\\widetilde {A}}{\\xcancel {A}}',
             skipOcaml: 'double spacing and extra braces'
         },
         'FUN_AR1 (2)': {
@@ -336,6 +335,10 @@ describe('Comprehensive test cases', function () {
             input: '\\overbrace {A} _{b}^{c}\\underbrace {C} _{d}^{e}',
             skipOcaml: 'ocaml bug'
         },
+        'FUN_AR1NB (4)': {
+            input: '\\xleftarrow{A}\\xrightarrow{A}',
+            output: '\\xleftarrow {A} \\xrightarrow {A} '
+        },
         FUN_AR1OPT: {
             input:
                 '\\sqrt{2}\\sqrt[3]{2}' +
@@ -343,8 +346,8 @@ describe('Comprehensive test cases', function () {
                 '\\xrightarrow{above}\\xrightarrow[below]{above}',
             output:
                 '{\\sqrt {2}}{\\sqrt[{3}]{2}}' +
-                '{\\xleftarrow {above}}{\\xleftarrow[{below}]{above}}' +
-                '{\\xrightarrow {above}}{\\xrightarrow[{below}]{above}}',
+                '\\xleftarrow {above} {\\xleftarrow[{below}]{above}}' +
+                '\\xrightarrow {above} {\\xrightarrow[{below}]{above}}',
             skipOcaml: 'spacing'
         },
         FUN_AR2: {