Metamath Proof Explorer


Theorem tposf2

Description: The domain and range of a transposition. (Contributed by NM, 10-Sep-2015)

Ref Expression
Assertion tposf2 ( Rel 𝐴 → ( 𝐹 : 𝐴𝐵 → tpos 𝐹 : 𝐴𝐵 ) )

Proof

Step Hyp Ref Expression
1 tposfo2 ( Rel 𝐴 → ( 𝐹 : 𝐴onto→ ran 𝐹 → tpos 𝐹 : 𝐴onto→ ran 𝐹 ) )
2 ffn ( 𝐹 : 𝐴𝐵𝐹 Fn 𝐴 )
3 dffn4 ( 𝐹 Fn 𝐴𝐹 : 𝐴onto→ ran 𝐹 )
4 2 3 sylib ( 𝐹 : 𝐴𝐵𝐹 : 𝐴onto→ ran 𝐹 )
5 1 4 impel ( ( Rel 𝐴𝐹 : 𝐴𝐵 ) → tpos 𝐹 : 𝐴onto→ ran 𝐹 )
6 fof ( tpos 𝐹 : 𝐴onto→ ran 𝐹 → tpos 𝐹 : 𝐴 ⟶ ran 𝐹 )
7 5 6 syl ( ( Rel 𝐴𝐹 : 𝐴𝐵 ) → tpos 𝐹 : 𝐴 ⟶ ran 𝐹 )
8 frn ( 𝐹 : 𝐴𝐵 → ran 𝐹𝐵 )
9 8 adantl ( ( Rel 𝐴𝐹 : 𝐴𝐵 ) → ran 𝐹𝐵 )
10 7 9 fssd ( ( Rel 𝐴𝐹 : 𝐴𝐵 ) → tpos 𝐹 : 𝐴𝐵 )
11 10 ex ( Rel 𝐴 → ( 𝐹 : 𝐴𝐵 → tpos 𝐹 : 𝐴𝐵 ) )