fix latex

docs/base-logic.tex

@@ -39,7 +39,7 @@ Below, $\melt$ ranges over $\monoid$ and $i$ ranges over $\set{1,2}$.
       \type \to \type
 \\[0.4em]
   \term, \prop, \pred \bnfdef{}&
-      \var \bm\mid
+      \var \mid
       \sigfn(\term_1, \dots, \term_n) \mid
       \textlog{abort}(\term) \mid
       () \mid