diff --git a/src/math/mathop/mathop.pysty b/src/math/mathop/mathop.pysty
index d185983..a90e75a 100644
--- a/src/math/mathop/mathop.pysty
+++ b/src/math/mathop/mathop.pysty
@@ -192,6 +192,11 @@ __END_OPTIONS_X__
 \newcommand\abelianization{^{\ab}}
 
 
+\NewDocumentCommand\set{m}
+  {
+    \left\{ #1 \right\}
+  }
+
 %Taken from user egreg on
 %   https://tex.stackexchange.com/a/22255
 \newcommand\frestriction[2]{{% we make the whole thing an ordinary symbol