Extension.Prelude
implies
singleton
unique
sortednub
sortednubBy
sortednubOn
nubOn
groupOn
sortOn
sortOnMemo
groupSortOn
eqClasses
eqClassesBy
splitBy
choose
leaveOneOut
keepFirst
swap
sortPair
isRight
isLeft
type Named a
flushRightBy
flushRight
flushLeftBy
flushLeft
warning
putErr
putErrLn
oneOfList
oneOfSet
oneOfMap
ifM
errorFree
errorFree1
unreachable