Metamath Proof Explorer


Theorem raleqbidvvOLD

Description: Version of raleqbidv with additional disjoint variable conditions, not requiring ax-8 nor df-clel . (Contributed by BJ, 22-Sep-2024) (New usage is discouraged.) (Proof modification is discouraged.)

Ref Expression
Hypotheses raleqbidvv.1 φA=B
raleqbidvv.2 φψχ
Assertion raleqbidvvOLD φxAψxBχ

Proof

Step Hyp Ref Expression
1 raleqbidvv.1 φA=B
2 raleqbidvv.2 φψχ
3 2 alrimiv φxψχ
4 dfcleq A=BxxAxB
5 1 4 sylib φxxAxB
6 19.26 xψχxAxBxψχxxAxB
7 3 5 6 sylanbrc φxψχxAxB
8 imbi12 xAxBψχxAψxBχ
9 8 impcom ψχxAxBxAψxBχ
10 7 9 sylg φxxAψxBχ
11 albi xxAψxBχxxAψxxBχ
12 10 11 syl φxxAψxxBχ
13 df-ral xAψxxAψ
14 df-ral xBχxxBχ
15 12 13 14 3bitr4g φxAψxBχ