Metamath Proof Explorer


Theorem dvelimdf

Description: Deduction form of dvelimf . Usage of this theorem is discouraged because it depends on ax-13 . (Contributed by NM, 7-Apr-2004) (Revised by Mario Carneiro, 6-Oct-2016) (Proof shortened by Wolf Lammen, 11-May-2018) (New usage is discouraged.)

Ref Expression
Hypotheses dvelimdf.1
|- F/ x ph
dvelimdf.2
|- F/ z ph
dvelimdf.3
|- ( ph -> F/ x ps )
dvelimdf.4
|- ( ph -> F/ z ch )
dvelimdf.5
|- ( ph -> ( z = y -> ( ps <-> ch ) ) )
Assertion dvelimdf
|- ( ph -> ( -. A. x x = y -> F/ x ch ) )

Proof

Step Hyp Ref Expression
1 dvelimdf.1
 |-  F/ x ph
2 dvelimdf.2
 |-  F/ z ph
3 dvelimdf.3
 |-  ( ph -> F/ x ps )
4 dvelimdf.4
 |-  ( ph -> F/ z ch )
5 dvelimdf.5
 |-  ( ph -> ( z = y -> ( ps <-> ch ) ) )
6 1 3 nfim1
 |-  F/ x ( ph -> ps )
7 2 4 nfim1
 |-  F/ z ( ph -> ch )
8 5 com12
 |-  ( z = y -> ( ph -> ( ps <-> ch ) ) )
9 8 pm5.74d
 |-  ( z = y -> ( ( ph -> ps ) <-> ( ph -> ch ) ) )
10 6 7 9 dvelimf
 |-  ( -. A. x x = y -> F/ x ( ph -> ch ) )
11 pm5.5
 |-  ( ph -> ( ( ph -> ch ) <-> ch ) )
12 1 11 nfbidf
 |-  ( ph -> ( F/ x ( ph -> ch ) <-> F/ x ch ) )
13 10 12 syl5ib
 |-  ( ph -> ( -. A. x x = y -> F/ x ch ) )