Metamath Proof Explorer


Theorem fnrndomnum

Description: A version of fnrndomg that does not require the axiom of choice ax-ac . (Contributed by Vincent Gonzalez, 17-Aug-2026)

Ref Expression
Assertion fnrndomnum ⊢ A ∈ dom ⁡ card → F Fn A → ran ⁡ F ≼ A

Proof

Step Hyp Ref Expression
1 dffn4 ⊢ F Fn A ↔ F : A ⟶ onto ran ⁡ F
2 fodomnum ⊢ A ∈ dom ⁡ card → F : A ⟶ onto ran ⁡ F → ran ⁡ F ≼ A
3 1 2 biimtrid ⊢ A ∈ dom ⁡ card → F Fn A → ran ⁡ F ≼ A