Metamath Proof Explorer


Theorem ss2abiOLD

Description: Obsolete version of ss2abi as of 28-Jun-2024. (Contributed by NM, 31-Mar-1995) (Proof modification is discouraged.) (New usage is discouraged.)

Ref Expression
Hypothesis ss2abiOLD.1 φ ψ
Assertion ss2abiOLD x | φ x | ψ

Proof

Step Hyp Ref Expression
1 ss2abiOLD.1 φ ψ
2 ss2ab x | φ x | ψ x φ ψ
3 2 1 mpgbir x | φ x | ψ