--- a/lib/texinputs/isabellesym.sty Sat Feb 27 20:42:13 2016 +0100
+++ b/lib/texinputs/isabellesym.sty Sat Feb 27 21:04:13 2016 +0100
@@ -222,6 +222,7 @@
\newcommand{\isasymexists}{\isamath{\exists\,}}
\newcommand{\isasymnot}{\isamath{\neg}}
\newcommand{\isasymnexists}{\isamath{\nexists\,}} %requires amssymb
+\newcommand{\isasymcircle}{\isamath{\ocircle}} %requires wasysym
\newcommand{\isasymbox}{\isamath{\Box}} %requires amssymb
\newcommand{\isasymdiamond}{\isamath{\Diamond}} %requires amssymb
\newcommand{\isasymdiamondop}{\isamath{\diamond}}