--- a/lib/texinputs/isabelle.sty Fri Jan 12 20:19:59 2018 +0100
+++ b/lib/texinputs/isabelle.sty Sat Jan 13 11:22:46 2018 +0100
@@ -41,6 +41,9 @@
\newenvironment{isaantiq}{{\isacharat\isacharbraceleft}}{{\isacharbraceright}}
+\newcommand{\isamarkupcancel}[1]{\xout{#1}} %requires \usepackage[normalem]{ulem}
+%OR: \newcommand{\isamarkupcancel}[1]{{\color{gray}{\isacharverbatimopen}#1{\isacharverbatimclose}}} %requires \usepackage{xcolor}
+
\newdimen\isa@parindent\newdimen\isa@parskip
\newenvironment{isabellebody}{%