Metamath Proof Explorer


Theorem oftpos

Description: The transposition of the value of a function operation for two functions is the value of the function operation for the two functions transposed. (Contributed by Stefan O'Rear, 17-Jul-2018)

Ref Expression
Assertion oftpos ⊢ F ∈ V ∧ G ∈ W → tpos F R f G = tpos F R f tpos G

Proof

Step Hyp Ref Expression
1 elex ⊢ F ∈ V → F ∈ V
2 1 adantr ⊢ F ∈ V ∧ G ∈ W → F ∈ V
3 elex ⊢ G ∈ W → G ∈ V
4 3 adantl ⊢ F ∈ V ∧ G ∈ W → G ∈ V
5 funmpt ⊢ Fun ⁡ x ∈ V × V ∪ ∅ ⟼ ⋃ x -1
6 5 a1i ⊢ F ∈ V ∧ G ∈ W → Fun ⁡ x ∈ V × V ∪ ∅ ⟼ ⋃ x -1
7 dftpos4 ⊢ tpos F = F ∘ x ∈ V × V ∪ ∅ ⟼ ⋃ x -1
8 tposexg ⊢ F ∈ V → tpos F ∈ V
9 8 adantr ⊢ F ∈ V ∧ G ∈ W → tpos F ∈ V
10 7 9 eqeltrrid ⊢ F ∈ V ∧ G ∈ W → F ∘ x ∈ V × V ∪ ∅ ⟼ ⋃ x -1 ∈ V
11 dftpos4 ⊢ tpos G = G ∘ x ∈ V × V ∪ ∅ ⟼ ⋃ x -1
12 tposexg ⊢ G ∈ W → tpos G ∈ V
13 12 adantl ⊢ F ∈ V ∧ G ∈ W → tpos G ∈ V
14 11 13 eqeltrrid ⊢ F ∈ V ∧ G ∈ W → G ∘ x ∈ V × V ∪ ∅ ⟼ ⋃ x -1 ∈ V
15 ofco2 ⊢ F ∈ V ∧ G ∈ V ∧ Fun ⁡ x ∈ V × V ∪ ∅ ⟼ ⋃ x -1 ∧ F ∘ x ∈ V × V ∪ ∅ ⟼ ⋃ x -1 ∈ V ∧ G ∘ x ∈ V × V ∪ ∅ ⟼ ⋃ x -1 ∈ V → F R f G ∘ x ∈ V × V ∪ ∅ ⟼ ⋃ x -1 = F ∘ x ∈ V × V ∪ ∅ ⟼ ⋃ x -1 R f G ∘ x ∈ V × V ∪ ∅ ⟼ ⋃ x -1
16 2 4 6 10 14 15 syl23anc ⊢ F ∈ V ∧ G ∈ W → F R f G ∘ x ∈ V × V ∪ ∅ ⟼ ⋃ x -1 = F ∘ x ∈ V × V ∪ ∅ ⟼ ⋃ x -1 R f G ∘ x ∈ V × V ∪ ∅ ⟼ ⋃ x -1
17 dftpos4 ⊢ tpos F R f G = F R f G ∘ x ∈ V × V ∪ ∅ ⟼ ⋃ x -1
18 7 11 oveq12i ⊢ tpos F R f tpos G = F ∘ x ∈ V × V ∪ ∅ ⟼ ⋃ x -1 R f G ∘ x ∈ V × V ∪ ∅ ⟼ ⋃ x -1
19 16 17 18 3eqtr4g ⊢ F ∈ V ∧ G ∈ W → tpos F R f G = tpos F R f tpos G