availNames (AvailTC n ns) = ns
-------------------------------------
-addSysAvails :: AvailInfo -> [Name] -> AvailInfo
-addSysAvails avail [] = avail
-addSysAvails (AvailTC n ns) sys = AvailTC n (sys ++ ns)
-
--------------------------------------
filterAvail :: RdrNameIE -- Wanted
-> AvailInfo -- Available
-> Maybe AvailInfo -- Resulting available;