Theorem f1of1

Description: A one-to-one onto mapping is a one-to-one mapping. (Contributed by NM, 12-Dec-2003)

	Ref	Expression
Assertion	f1of1	⊢ ( 𝐹 : 𝐴 –1-1-onto→ 𝐵 → 𝐹 : 𝐴 –1-1→ 𝐵 )

Proof

Step	Hyp	Ref	Expression
1		df-f1o	⊢ ( 𝐹 : 𝐴 –1-1-onto→ 𝐵 ↔ ( 𝐹 : 𝐴 –1-1→ 𝐵 ∧ 𝐹 : 𝐴 –onto→ 𝐵 ) )
2	1	simplbi	⊢ ( 𝐹 : 𝐴 –1-1-onto→ 𝐵 → 𝐹 : 𝐴 –1-1→ 𝐵 )