Theorem syl221anc 1193

Description: Syllogism combined with contraction. (Contributed by NM, 11-Mar-2012.)

Hypotheses

Ref	Expression
sylXanc.1	|- (ph -> ps)
sylXanc.2	|- (ph -> ch)
sylXanc.3	|- (ph -> th)
sylXanc.4	|- (ph -> ta)
sylXanc.5	|- (ph -> et)
syl221anc.6	|- (((ps /\ ch) /\ (th /\ ta) /\ et) -> ze)

Assertion

Ref	Expression
syl221anc	|- (ph -> ze)

Proof of Theorem syl221anc

Step	Hyp	Ref	Expression
1		sylXanc.1	. 2 |- (ph -> ps)
2		sylXanc.2	. 2 |- (ph -> ch)
3		sylXanc.3	. . 3 |- (ph -> th)
4		sylXanc.4	. . 3 |- (ph -> ta)
5	3, 4	jca 518	. 2 |- (ph -> (th /\ ta))
6		sylXanc.5	. 2 |- (ph -> et)
7		syl221anc.6	. 2 |- (((ps /\ ch) /\ (th /\ ta) /\ et) -> ze)
8	1, 2, 5, 6, 7	syl211anc 1188	1 |- (ph -> ze)

Syntax hints:   -> wi 4   /\ wa 358   /\ w3a 934

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8

This theorem depends on definitions:  df-bi 177  df-an 360  df-3an 936

This theorem is referenced by:  syl222anc  1198  vtocldf  2907  iota2df  4366  nnpweq  4524  sfindbl  4531