From 39e907ed2c6191cfc503ee088b7dea3a49400109 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Maximilian=20Ke=C3=9Fler=20=28via=20gitlab=20runner=29?=
 <git@maximilian-kessler.de>
Date: Mon, 25 Oct 2021 12:08:15 +0200
Subject: [PATCH] add restriction operator

---
 src/math/mathop.pysty | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/src/math/mathop.pysty b/src/math/mathop.pysty
index 1337941..9f19d58 100644
--- a/src/math/mathop.pysty
+++ b/src/math/mathop.pysty
@@ -193,3 +193,13 @@ __END_OPTIONS_X__
 
 \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
+}}