Numeric.MixedTypes.AddSub
type CanAdd t1 t2
class CanAddAsymmetric t1 t2
type CanAddThis t1 t2
type CanAddSameType t
(+)
sum
specCanAdd
specCanAddNotMixed
specCanAddSameType
class CanSub t1 t2
type CanSubThis t1 t2
type CanSubSameType t
(-)
specCanSub
specCanSubNotMixed