Theorem sbctt 3108

Description: Substitution for a variable not free in a wff does not affect it. (Contributed by Mario Carneiro, 14-Oct-2016.)

Assertion

Ref	Expression
sbctt	|- ((A e. V /\ F/xph) -> ( [.A / x ].ph <-> ph))

Proof of Theorem sbctt

Dummy variable y is distinct from all other variables.

Step	Hyp	Ref	Expression
1		dfsbcq2 3049	. . . . 5 |- (y = A -> ([y / x]ph <-> [.A / x ].ph))
2	1	bibi1d 310	. . . 4 |- (y = A -> (([y / x]ph <-> ph) <-> ( [.A / x ].ph <-> ph)))
3	2	imbi2d 307	. . 3 |- (y = A -> (( F/xph -> ([y / x]ph <-> ph)) <-> ( F/xph -> ( [.A / x ].ph <-> ph))))
4		sbft 2025	. . 3 |- ( F/xph -> ([y / x]ph <-> ph))
5	3, 4	vtoclg 2914	. 2 |- (A e. V -> ( F/xph -> ( [.A / x ].ph <-> ph)))
6	5	imp 418	1 |- ((A e. V /\ F/xph) -> ( [.A / x ].ph <-> ph))

Syntax hints:   -> wi 4   <-> wb 176   /\ wa 358   F/wnf 1544   = wceq 1642  [wsb 1648   e. wcel 1710   [.wsbc 3046

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1546  ax-5 1557  ax-17 1616  ax-9 1654  ax-8 1675  ax-6 1729  ax-7 1734  ax-11 1746  ax-12 1925  ax-ext 2334

This theorem depends on definitions:  df-bi 177  df-or 359  df-an 360  df-tru 1319  df-ex 1542  df-nf 1545  df-sb 1649  df-clab 2340  df-cleq 2346  df-clel 2349  df-nfc 2478  df-v 2861  df-sbc 3047

This theorem is referenced by:  sbcgf  3109  csbtt  3148