Theorem fdmd 38415

Description: The domain of a mapping. (Contributed by Glauco Siliprandi, 26-Jun-2021.)

Hypothesis

Ref	Expression
fdmd.1	⊢ (𝜑 → 𝐹:𝐴⟶𝐵)

Assertion

Ref	Expression
fdmd	⊢ (𝜑 → dom 𝐹 = 𝐴)

Proof of Theorem fdmd

Step	Hyp	Ref	Expression
1		fdmd.1	. 2 ⊢ (𝜑 → 𝐹:𝐴⟶𝐵)
2		fdm 5964	. 2 ⊢ (𝐹:𝐴⟶𝐵 → dom 𝐹 = 𝐴)
3	1, 2	syl 17	1 ⊢ (𝜑 → dom 𝐹 = 𝐴)

Syntax hints:   → wi 4   = wceq 1475  dom cdm 5038  ⟶wf 5800

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8

This theorem depends on definitions:  df-bi 196  df-an 385  df-fn 5807  df-f 5808

This theorem is referenced by:  issmfd  39621  issmfdf  39624  cnfsmf  39627  issmfled  39644  smfmbfcex  39646  issmfgtd  39647