supported by all Unix flavours and, worse, they cannot be used with
\helpref{wxCondition}{wxcondition}.
-For example, when several thread use the data stored in the linked list,
-modifications to the list should be only allowed to one thread at a time
+For example, when several threads use the data stored in the linked list,
+modifications to the list should only be allowed to one thread at a time
because during a new node addition the list integrity is temporarily broken
(this is also called {\it program invariant}).