Theorem fndmd

Description: The domain of a function. (Contributed by Glauco Siliprandi, 23-Oct-2021)

	Ref	Expression
Hypothesis	fndmd.1	$$⊢\phi \to FFnA$$
Assertion	fndmd	$$⊢\phi \to \mathrm{dom}F=A$$

Proof

Step	Hyp	Ref	Expression
1		fndmd.1	$$⊢\phi \to FFnA$$
2		fndm	$$⊢FFnA\to \mathrm{dom}F=A$$
3	1 2	syl	$$⊢\phi \to \mathrm{dom}F=A$$