Metamath Proof Explorer


Theorem zfrep3cl

Description: An inference based on the Axiom of Replacement. Typically, ph defines a function from x to y . (Contributed by NM, 26-Nov-1995)

Ref Expression
Hypotheses zfrep3cl.1 𝐴 ∈ V
zfrep3cl.2 ( 𝑥𝐴 → ∃ 𝑧𝑦 ( 𝜑𝑦 = 𝑧 ) )
Assertion zfrep3cl 𝑧𝑦 ( 𝑦𝑧 ↔ ∃ 𝑥 ( 𝑥𝐴𝜑 ) )

Proof

Step Hyp Ref Expression
1 zfrep3cl.1 𝐴 ∈ V
2 zfrep3cl.2 ( 𝑥𝐴 → ∃ 𝑧𝑦 ( 𝜑𝑦 = 𝑧 ) )
3 nfcv 𝑥 𝐴
4 3 1 2 zfrepclf 𝑧𝑦 ( 𝑦𝑧 ↔ ∃ 𝑥 ( 𝑥𝐴𝜑 ) )