Theorem fndmi 5481

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

Hypothesis

Ref	Expression
fndmi.1	⊢ 𝐹 Fn 𝐴

Assertion

Ref	Expression
fndmi	⊢ dom 𝐹 = 𝐴

Proof of Theorem fndmi

Step	Hyp	Ref	Expression
1		fndmi.1	. 2 ⊢ 𝐹 Fn 𝐴
2		fndm 5480	. 2 ⊢ (𝐹 Fn 𝐴 → dom 𝐹 = 𝐴)
3	1, 2	ax-mp 5	1 ⊢ dom 𝐹 = 𝐴

This proof depends on syntax axioms:   = wceq 1402  dom cdm 4774   Fn wfn 5372

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107

This proof depends on definitions:  df-bi 117  df-fn 5380

This theorem is used by:  pfxclz  11453