Metamath Proof Explorer


Theorem bnj1422

Description: First-order logic and set theory. (Contributed by Jonathan Ben-Naim, 3-Jun-2011) (New usage is discouraged.)

Ref Expression
Hypotheses bnj1422.1 ⊢ φ → Fun ⁡ A
bnj1422.2 ⊢ φ → dom ⁡ A = B
Assertion bnj1422 ⊢ φ → A Fn B

Proof

Step Hyp Ref Expression
1 bnj1422.1 ⊢ φ → Fun ⁡ A
2 bnj1422.2 ⊢ φ → dom ⁡ A = B
3 df-fn ⊢ A Fn B ↔ Fun ⁡ A ∧ dom ⁡ A = B
4 1 2 3 sylanbrc ⊢ φ → A Fn B