.# package:grisette

>>> let f :: Integer -> Union Integer = \x -> mrgIf (ssym "a") (mrgSingle $ x + 1) (mrgSingle $ x + 2)

>>> f .# (mrgIf (ssym "b" :: SymBool) (mrgSingle 0) (mrgSingle 2) :: Union Integer)
{If (&& b a) 1 (If b 2 (If a 3 4))}