--- a/style.sty	Fri Oct 25 17:23:23 2019 +0100
+++ b/style.sty	Sun Oct 27 11:16:09 2019 +0000
@@ -14,10 +14,13 @@
 \newcommand{\ZERO}{\mbox{\bf 0}}
 \newcommand{\ONE}{\mbox{\bf 1}}
 \newcommand{\Left}{\textit{Left}}
+\newcommand{\Right}{\textit{Right}}
 \newcommand{\Der}{\textit{Der}}
 \newcommand{\der}{\textit{der}}
 \newcommand{\Ders}{\textit{Ders}}
 \newcommand{\ders}{\textit{ders}}
+\newcommand{\inj}{\textit{inj}}
+\newcommand{\nullable}{\textit{nullable}}
 
 %%% for trees
 %% http://anorien.csc.warwick.ac.uk/mirrors/CTAN/graphics/pgf/contrib/forest/forest.pdf