Metamath Proof Explorer


Theorem alrimii

Description: A lemma for introducing a universal quantifier, in inference form. (Contributed by Giovanni Mascellani, 30-May-2019)

Ref Expression
Hypotheses alrimii.1
|- F/ y ph
alrimii.2
|- ( ph -> ps )
alrimii.3
|- ( [. y / x ]. ch <-> ps )
alrimii.4
|- F/ y ch
Assertion alrimii
|- ( ph -> A. x ch )

Proof

Step Hyp Ref Expression
1 alrimii.1
 |-  F/ y ph
2 alrimii.2
 |-  ( ph -> ps )
3 alrimii.3
 |-  ( [. y / x ]. ch <-> ps )
4 alrimii.4
 |-  F/ y ch
5 2 3 sylibr
 |-  ( ph -> [. y / x ]. ch )
6 1 5 alrimi
 |-  ( ph -> A. y [. y / x ]. ch )
7 nfsbc1v
 |-  F/ x [. y / x ]. ch
8 sbceq2a
 |-  ( y = x -> ( [. y / x ]. ch <-> ch ) )
9 7 4 8 cbvalv1
 |-  ( A. y [. y / x ]. ch <-> A. x ch )
10 6 9 sylib
 |-  ( ph -> A. x ch )