DEFINITION ex3_4_ind()
TYPE =
∀A0:Set
.∀A1:Set
.∀A2:Set
.∀A3:Set
.∀P0:A0→A1→A2→A3→Prop
.∀P1:A0→A1→A2→A3→Prop
.∀P2:A0→A1→A2→A3→Prop
.∀P:Prop.(∀a:A0.∀a1:A1.∀a2:A2.∀a3:A3.(P0 a a1 a2 a3)→(P1 a a1 a2 a3)→(P2 a a1 a2 a3)→P)→(ex3_4 A0 A1 A2 A3 P0 P1 P2)→P
BODY =
Show proof