Metamath Proof Explorer


Theorem f1orn

Description: A one-to-one function maps onto its range. (Contributed by NM, 13-Aug-2004)

Ref Expression
Assertion f1orn ( 𝐹 : 𝐴1-1-onto→ ran 𝐹 ↔ ( 𝐹 Fn 𝐴 ∧ Fun 𝐹 ) )

Proof

Step Hyp Ref Expression
1 dff1o2 ( 𝐹 : 𝐴1-1-onto→ ran 𝐹 ↔ ( 𝐹 Fn 𝐴 ∧ Fun 𝐹 ∧ ran 𝐹 = ran 𝐹 ) )
2 eqid ran 𝐹 = ran 𝐹
3 df-3an ( ( 𝐹 Fn 𝐴 ∧ Fun 𝐹 ∧ ran 𝐹 = ran 𝐹 ) ↔ ( ( 𝐹 Fn 𝐴 ∧ Fun 𝐹 ) ∧ ran 𝐹 = ran 𝐹 ) )
4 2 3 mpbiran2 ( ( 𝐹 Fn 𝐴 ∧ Fun 𝐹 ∧ ran 𝐹 = ran 𝐹 ) ↔ ( 𝐹 Fn 𝐴 ∧ Fun 𝐹 ) )
5 1 4 bitri ( 𝐹 : 𝐴1-1-onto→ ran 𝐹 ↔ ( 𝐹 Fn 𝐴 ∧ Fun 𝐹 ) )