Fix unbalanced parethesis.
diff --git a/Doc/lib/libexcs.tex b/Doc/lib/libexcs.tex
index 54b141a..b8d8f7c 100644
--- a/Doc/lib/libexcs.tex
+++ b/Doc/lib/libexcs.tex
@@ -189,7 +189,7 @@
   interrupts is made regularly.
 % XXXJH xrefs here
   Interrupts typed when a built-in function \function{input()} or
-  \function{raw_input()}) is waiting for input also raise this
+  \function{raw_input()} is waiting for input also raise this
   exception.
 \end{excdesc}