%************************************************************************
\begin{code}
-data PatCtxt = LamPat Bool | LetPat TcSigFun
+data PatCtxt = LamPat Bool -- Used for lambda, case, do-notation etc
+ | LetPat TcSigFun -- Used for let(rec) bindings
-- True <=> we are checking the case expression,
-- so can do full-blown refinement
-- False <=> inferring, do no refinement