Phoebe
	Φ₂:=λabcde.ad(be)(ce)
	Use:
	  scanl1' := Φ₂ scanl head tail
	  foldl1' := Φ₂ foldl head tail
	Combinator: C**(C*Φ*)
	SK-Form:
	((S(K(S(K((S((S(K((S(KS))K)))S))(KK))))))
	((S(K((S((S(K((S(KS))K)))S))(KK))))
	(S(K((S(K(S(KS))))((S(KS))K))))))