diff --git a/src/math/mathop.pysty b/src/math/mathop.pysty
index a501017..4a0c668 100644
--- a/src/math/mathop.pysty
+++ b/src/math/mathop.pysty
@@ -170,6 +170,9 @@ __END_OPTIONS_X__
 %% Algebraic geometry
 \DeclareSimpleMathOperator{eq}
 \DeclareSimpleMathOperator{Idem}
+\DeclareSimpleMathOperator{Supp}
+\DeclareSimpleMathOperator{Ann}
+\DeclareSimpleMathOperator{OC}
 
 % Characteristic function
 \newcommand*{\cfun}{\ensuremath{\mathbbm{1}}}