Description: A one-to-one function maps one-to-one onto its range. (Contributed by NM, 4-Sep-2004)
Ref | Expression | ||
---|---|---|---|
Assertion | f1f1orn | ⊢ ( 𝐹 : 𝐴 –1-1→ 𝐵 → 𝐹 : 𝐴 –1-1-onto→ ran 𝐹 ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | f1fn | ⊢ ( 𝐹 : 𝐴 –1-1→ 𝐵 → 𝐹 Fn 𝐴 ) | |
2 | df-f1 | ⊢ ( 𝐹 : 𝐴 –1-1→ 𝐵 ↔ ( 𝐹 : 𝐴 ⟶ 𝐵 ∧ Fun ◡ 𝐹 ) ) | |
3 | 2 | simprbi | ⊢ ( 𝐹 : 𝐴 –1-1→ 𝐵 → Fun ◡ 𝐹 ) |
4 | f1orn | ⊢ ( 𝐹 : 𝐴 –1-1-onto→ ran 𝐹 ↔ ( 𝐹 Fn 𝐴 ∧ Fun ◡ 𝐹 ) ) | |
5 | 1 3 4 | sylanbrc | ⊢ ( 𝐹 : 𝐴 –1-1→ 𝐵 → 𝐹 : 𝐴 –1-1-onto→ ran 𝐹 ) |