Metamath Proof Explorer


Theorem fnrndomgOLD

Description: Obsolete version of fnrndomg as of 18-Aug-2026. (Contributed by NM, 1-Sep-2004) (Proof modification is discouraged.) (New usage is discouraged.)

Ref Expression
Assertion fnrndomgOLD ⊢ A ∈ B → F Fn A → ran ⁡ F ≼ A

Proof

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