diff --git a/build_info.json b/build_info.json
index 621046a..d1ccdb4 100644
--- a/build_info.json
+++ b/build_info.json
@@ -1,8 +1,8 @@
 {
     "build_time": "",
     "source files": {
-        "version": "v2.2.2-13",
-        "commit": "ad29266e4ad52baf039adfd100c6dd6ac7e4be60",
+        "version": "v2.2.2-14",
+        "commit": "39e907ed2c6191cfc503ee088b7dea3a49400109",
         "dirty": false
     },
     "pytex": {
@@ -144,9 +144,9 @@
         {
             "name": "mkessler-mathop.sty",
             "source file": "mathop.pysty",
-            "build time": "2021/10/25 07:11",
-            "source version": "v2.2.2-13",
-            "source commit hash": "ad29266e4ad52baf039adfd100c6dd6ac7e4be60",
+            "build time": "2021/10/25 10:09",
+            "source version": "v2.2.2-14",
+            "source commit hash": "39e907ed2c6191cfc503ee088b7dea3a49400109",
             "pytex version": "v1.0.0-18",
             "pytex commit hash": "126d420b7a6ed2d4b2a42d534ab2e12344869643",
             "dirty": false
diff --git a/math/mkessler-mathop.sty b/math/mkessler-mathop.sty
index f64005c..dd23da8 100644
--- a/math/mkessler-mathop.sty
+++ b/math/mkessler-mathop.sty
@@ -27,7 +27,7 @@
 % 
 % Build details:
 %   PyTeX version: v1.0.0-18 (commit 126d420)
-%   Source code version: v2.2.2-13 (commit ad29266)
+%   Source code version: v2.2.2-14 (commit 39e907e)
 % 
 % This LaTeX package is free software and distributed under the MIT License. You
 % may use it freely for your purposes. The latest version of the package can be
@@ -241,3 +241,13 @@
 
 \newcommand\ab{\text{ab}}
 \newcommand\abelianization{^{\ab}}
+
+
+%Taken from user egreg on
+%   https://tex.stackexchange.com/a/22255
+\newcommand\restriction[2]{{% we make the whole thing an ordinary symbol
+  \left.\kern-\nulldelimiterspace % automatically resize the bar with \right
+  #1 % the function
+  \vphantom{\big|} % pretend it's a little taller at normal size
+  \right|_{#2} % this is the delimiter
+}}