Fix example regular expressions that simulate scanf() constructs.
diff --git a/Doc/lib/libre.tex b/Doc/lib/libre.tex
index d48b1b8..7482b9c 100644
--- a/Doc/lib/libre.tex
+++ b/Doc/lib/libre.tex
@@ -860,11 +860,11 @@
\lineii{\code{\%5c}}
{\regexp{.\{5\}}}
\lineii{\code{\%d}}
- {\regexp{[-+]\e d+}}
+ {\regexp{[-+]?\e d+}}
\lineii{\code{\%e}, \code{\%E}, \code{\%f}, \code{\%g}}
- {\regexp{[-+](\e d+(\e.\e d*)?|\e d*\e.\e d+)([eE]\e d+)?}}
+ {\regexp{[-+]?(\e d+(\e.\e d*)?|\e d*\e.\e d+)([eE]\e d+)?}}
\lineii{\code{\%i}}
- {\regexp{[-+](0[xX][\e dA-Fa-f]+|0[0-7]*|\e d+)}}
+ {\regexp{[-+]?(0[xX][\e dA-Fa-f]+|0[0-7]*|\e d+)}}
\lineii{\code{\%o}}
{\regexp{0[0-7]*}}
\lineii{\code{\%s}}