Metamath Proof Explorer


Theorem setrec2v

Description: Version of setrec2 with a disjoint variable condition instead of a nonfreeness hypothesis. (Contributed by Emmett Weisz, 6-Mar-2021)

Ref Expression
Hypotheses setrec2.b ⊢ 𝐵 = setrecs ( 𝐹 )
setrec2.c ⊢ ( 𝜑 → ∀ 𝑎 ( 𝑎 ⊆ 𝐶 → ( 𝐹 ‘ 𝑎 ) ⊆ 𝐶 ) )
Assertion setrec2v ( 𝜑 → 𝐵 ⊆ 𝐶 )

Proof

Step Hyp Ref Expression
1 setrec2.b ⊢ 𝐵 = setrecs ( 𝐹 )
2 setrec2.c ⊢ ( 𝜑 → ∀ 𝑎 ( 𝑎 ⊆ 𝐶 → ( 𝐹 ‘ 𝑎 ) ⊆ 𝐶 ) )
3 nfcv ⊢ Ⅎ 𝑎 𝐹
4 3 1 2 setrec2 ⊢ ( 𝜑 → 𝐵 ⊆ 𝐶 )