Theorem fndmd 5360

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

Hypothesis

Ref	Expression
fndmd.1	⊢ (𝜑 → 𝐹 Fn 𝐴)

Assertion

Ref	Expression
fndmd	⊢ (𝜑 → dom 𝐹 = 𝐴)

Proof of Theorem fndmd

Step	Hyp	Ref	Expression
1		fndmd.1	. 2 ⊢ (𝜑 → 𝐹 Fn 𝐴)
2		fndm 5358	. 2 ⊢ (𝐹 Fn 𝐴 → dom 𝐹 = 𝐴)
3	1, 2	syl 14	1 ⊢ (𝜑 → dom 𝐹 = 𝐴)

Syntax hints:   → wi 4   = wceq 1364  dom cdm 4664   Fn wfn 5254

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107

This theorem depends on definitions:  df-bi 117  df-fn 5262

This theorem is referenced by:  prdsbas2  12981  prdsplusgval  12985  prdsmulrval  12987