.||

(.||) :: (b -> c) -> Strategy b -> (a -> b) -> (a -> c)
parallel Control.Parallel.Strategies
Parallel function composition. The result of the second function is evaluated using the given strategy, in parallel with the application of the first function.
(.||.) :: (Testable prop1, Testable prop2) => prop1 -> prop2 -> Property
QuickCheck Test.QuickCheck.Property, QuickCheck Test.QuickCheck
Disjunction: p1 .||. p2 passes unless p1 and p2 simultaneously fail.