Metamath Proof Explorer


Theorem mpteq2daOLD

Description: Obsolete version of mpteq2da as of 11-Nov-2024. (Contributed by FL, 14-Sep-2013) (Revised by Mario Carneiro, 16-Dec-2013) (Proof modification is discouraged.) (New usage is discouraged.)

Ref Expression
Hypotheses mpteq2da.1 𝑥 𝜑
mpteq2da.2 ( ( 𝜑𝑥𝐴 ) → 𝐵 = 𝐶 )
Assertion mpteq2daOLD ( 𝜑 → ( 𝑥𝐴𝐵 ) = ( 𝑥𝐴𝐶 ) )

Proof

Step Hyp Ref Expression
1 mpteq2da.1 𝑥 𝜑
2 mpteq2da.2 ( ( 𝜑𝑥𝐴 ) → 𝐵 = 𝐶 )
3 eqid 𝐴 = 𝐴
4 3 ax-gen 𝑥 𝐴 = 𝐴
5 2 ex ( 𝜑 → ( 𝑥𝐴𝐵 = 𝐶 ) )
6 1 5 ralrimi ( 𝜑 → ∀ 𝑥𝐴 𝐵 = 𝐶 )
7 mpteq12f ( ( ∀ 𝑥 𝐴 = 𝐴 ∧ ∀ 𝑥𝐴 𝐵 = 𝐶 ) → ( 𝑥𝐴𝐵 ) = ( 𝑥𝐴𝐶 ) )
8 4 6 7 sylancr ( 𝜑 → ( 𝑥𝐴𝐵 ) = ( 𝑥𝐴𝐶 ) )