Theorem 19.20dvv 1291

Description: Deduction from Theorem 19.22 of [Margaris] p. 90.

Hypothesis

Ref	Expression
19.20dvv.1	|- (ph -> (ps -> ch))

Assertion

Ref	Expression
19.20dvv	|- (ph -> (A.xA.yps -> A.xA.ych))

Distinct variable groups:   ph,x   ph,y

Proof of Theorem 19.20dvv

Step	Hyp	Ref	Expression
1		19.20dvv.1	. . 3 |- (ph -> (ps -> ch))
2	1	19.20dv 1289	. 2 |- (ph -> (A.yps -> A.ych))
3	2	19.20dv 1289	1 |- (ph -> (A.xA.yps -> A.xA.ych))

Syntax hints:   -> wi 3  A.wal 954

This theorem was proved from axioms:  ax-1 4  ax-2 5  ax-mp 7  ax-gen 963  ax-17 971  ax-4 973  ax-5o 975

Copyright terms: Public domain