Metamath Proof Explorer


Theorem fmptdff

Description: A version of fmptd using bound-variable hypothesis instead of a distinct variable condition for ph . (Contributed by Glauco Siliprandi, 5-Jan-2025)

Ref Expression
Hypotheses fmptdff.1 ⊢ Ⅎ x φ
fmptdff.2 ⊢ Ⅎ _ x A
fmptdff.3 ⊢ Ⅎ _ x C
fmptdff.4 ⊢ φ ∧ x ∈ A → B ∈ C
fmptdff.5 ⊢ F = x ∈ A ⟼ B
Assertion fmptdff ⊢ φ → F : A ⟶ C

Proof

Step Hyp Ref Expression
1 fmptdff.1 ⊢ Ⅎ x φ
2 fmptdff.2 ⊢ Ⅎ _ x A
3 fmptdff.3 ⊢ Ⅎ _ x C
4 fmptdff.4 ⊢ φ ∧ x ∈ A → B ∈ C
5 fmptdff.5 ⊢ F = x ∈ A ⟼ B
6 1 4 ralrimia ⊢ φ → ∀ x ∈ A B ∈ C
7 2 3 5 fmptff ⊢ ∀ x ∈ A B ∈ C ↔ F : A ⟶ C
8 6 7 sylib ⊢ φ → F : A ⟶ C