finish updates on sec 3 (biggest changes)

jfp-paper/defs.tex

@@ -9,6 +9,9 @@
 \NewEnviron{longproof}{%
   \iflong\begin{proof}\BODY \end{proof}\fi%
 }
+\NewEnviron{shortproof}{%
+  \ifshort\begin{proof}\BODY \end{proof}\fi%
+}
 \NewEnviron{longfigure}{%
   \iflong\begin{figure}\BODY \end{figure}\fi%
 }