Remove redundant reference to tab (since it = 'horizontal tab')
diff --git a/Doc/lib/libascii.tex b/Doc/lib/libascii.tex
index 76db526..f3a1655 100644
--- a/Doc/lib/libascii.tex
+++ b/Doc/lib/libascii.tex
@@ -104,7 +104,7 @@
 \end{funcdesc}
 
 \begin{funcdesc}{isspace}{c}
-Checks for \ASCII{} white-space characters; space, tab, line feed,
+Checks for \ASCII{} white-space characters; space, line feed,
 carriage return, form feed, horizontal tab, vertical tab.
 \end{funcdesc}