Metamath Proof Explorer


Theorem findfvcl

Description: Please add description here. (Contributed by Jeff Hoffman, 12-Feb-2008)

Ref Expression
Hypotheses findfvcl.1 ( 𝜑 → ( 𝐹 ‘ ∅ ) ∈ 𝑃 )
findfvcl.2 ( 𝑦 ∈ ω → ( 𝜑 → ( ( 𝐹𝑦 ) ∈ 𝑃 → ( 𝐹 ‘ suc 𝑦 ) ∈ 𝑃 ) ) )
Assertion findfvcl ( 𝐴 ∈ ω → ( 𝜑 → ( 𝐹𝐴 ) ∈ 𝑃 ) )

Proof

Step Hyp Ref Expression
1 findfvcl.1 ( 𝜑 → ( 𝐹 ‘ ∅ ) ∈ 𝑃 )
2 findfvcl.2 ( 𝑦 ∈ ω → ( 𝜑 → ( ( 𝐹𝑦 ) ∈ 𝑃 → ( 𝐹 ‘ suc 𝑦 ) ∈ 𝑃 ) ) )
3 fveleq ( 𝑥 = ∅ → ( ( 𝜑 → ( 𝐹𝑥 ) ∈ 𝑃 ) ↔ ( 𝜑 → ( 𝐹 ‘ ∅ ) ∈ 𝑃 ) ) )
4 fveleq ( 𝑥 = 𝑦 → ( ( 𝜑 → ( 𝐹𝑥 ) ∈ 𝑃 ) ↔ ( 𝜑 → ( 𝐹𝑦 ) ∈ 𝑃 ) ) )
5 fveleq ( 𝑥 = suc 𝑦 → ( ( 𝜑 → ( 𝐹𝑥 ) ∈ 𝑃 ) ↔ ( 𝜑 → ( 𝐹 ‘ suc 𝑦 ) ∈ 𝑃 ) ) )
6 fveleq ( 𝑥 = 𝐴 → ( ( 𝜑 → ( 𝐹𝑥 ) ∈ 𝑃 ) ↔ ( 𝜑 → ( 𝐹𝐴 ) ∈ 𝑃 ) ) )
7 2 a2d ( 𝑦 ∈ ω → ( ( 𝜑 → ( 𝐹𝑦 ) ∈ 𝑃 ) → ( 𝜑 → ( 𝐹 ‘ suc 𝑦 ) ∈ 𝑃 ) ) )
8 3 4 5 6 1 7 finds ( 𝐴 ∈ ω → ( 𝜑 → ( 𝐹𝐴 ) ∈ 𝑃 ) )