Theorem fndmi

Description: The domain of a function. (Contributed by Wolf Lammen, 1-Jun-2024)

	Ref	Expression
Hypothesis	fndmi.1	|- F Fn A
Assertion	fndmi	|- dom F = A

Proof

Step	Hyp	Ref	Expression
1		fndmi.1	|- F Fn A
2		fndm	|- ( F Fn A -> dom F = A )
3	1 2	ax-mp	|- dom F = A