Description: A one-to-one function maps onto its range. (Contributed by NM, 13-Aug-2004)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | f1orn | ⊢ ( 𝐹 : 𝐴 –1-1-onto→ ran 𝐹 ↔ ( 𝐹 Fn 𝐴 ∧ Fun ◡ 𝐹 ) ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | dff1o2 | ⊢ ( 𝐹 : 𝐴 –1-1-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 : 𝐴 –1-1-onto→ ran 𝐹 ↔ ( 𝐹 Fn 𝐴 ∧ Fun ◡ 𝐹 ) ) |