Metamath Proof Explorer


Theorem ffunOLD

Description: Obsolete version of ffun as of 10-Jun-2026. (Contributed by NM, 3-Aug-1994) (Proof modification is discouraged.) (New usage is discouraged.)

Ref Expression
Assertion ffunOLD ( 𝐹 : 𝐴𝐵 → Fun 𝐹 )

Proof

Step Hyp Ref Expression
1 ffn ( 𝐹 : 𝐴𝐵𝐹 Fn 𝐴 )
2 fnfun ( 𝐹 Fn 𝐴 → Fun 𝐹 )
3 1 2 syl ( 𝐹 : 𝐴𝐵 → Fun 𝐹 )