pop(): An arbitrary element is removed, not a random element.
diff --git a/Doc/lib/libsets.tex b/Doc/lib/libsets.tex
index b029abe..74d09c7 100644
--- a/Doc/lib/libsets.tex
+++ b/Doc/lib/libsets.tex
@@ -143,7 +143,8 @@
{Removes element \var{x} from set \var{s} like \var{s}.remove(\var{x})
but does not raise a KeyError if \var{x} is not in \var{s}}
\lineii{\var{s}.pop()}
- {Remove and return a randomly-chosen element from \var{s}}
+ {Remove and return an element from \var{s}; no guarantee is
+ made about which element is removed}
\lineii{\var{s}.update(\var{t})}
{Add elements from \var{t} to set \var{s}}
\lineii{\var{s}.clear()}