Metamath Proof Explorer


Theorem pprodcnveq

Description: A converse law for parallel product. (Contributed by Scott Fenton, 3-May-2014)

Ref Expression
Assertion pprodcnveq ⊢ pprod R S = pprod R -1 S -1 -1

Proof

Step Hyp Ref Expression
1 dfpprod2 ⊢ pprod R S = 1 st ↾ V × V -1 ∘ R ∘ 1 st ↾ V × V ∩ 2 nd ↾ V × V -1 ∘ S ∘ 2 nd ↾ V × V
2 dfpprod2 ⊢ pprod R -1 S -1 = 1 st ↾ V × V -1 ∘ R -1 ∘ 1 st ↾ V × V ∩ 2 nd ↾ V × V -1 ∘ S -1 ∘ 2 nd ↾ V × V
3 2 cnveqi ⊢ pprod R -1 S -1 -1 = 1 st ↾ V × V -1 ∘ R -1 ∘ 1 st ↾ V × V ∩ 2 nd ↾ V × V -1 ∘ S -1 ∘ 2 nd ↾ V × V -1
4 cnvin ⊢ 1 st ↾ V × V -1 ∘ R -1 ∘ 1 st ↾ V × V ∩ 2 nd ↾ V × V -1 ∘ S -1 ∘ 2 nd ↾ V × V -1 = 1 st ↾ V × V -1 ∘ R -1 ∘ 1 st ↾ V × V -1 ∩ 2 nd ↾ V × V -1 ∘ S -1 ∘ 2 nd ↾ V × V -1
5 cnvco1 ⊢ 1 st ↾ V × V -1 ∘ R -1 ∘ 1 st ↾ V × V -1 = R -1 ∘ 1 st ↾ V × V -1 ∘ 1 st ↾ V × V
6 cnvco1 ⊢ R -1 ∘ 1 st ↾ V × V -1 = 1 st ↾ V × V -1 ∘ R
7 6 coeq1i ⊢ R -1 ∘ 1 st ↾ V × V -1 ∘ 1 st ↾ V × V = 1 st ↾ V × V -1 ∘ R ∘ 1 st ↾ V × V
8 coass ⊢ 1 st ↾ V × V -1 ∘ R ∘ 1 st ↾ V × V = 1 st ↾ V × V -1 ∘ R ∘ 1 st ↾ V × V
9 5 7 8 3eqtri ⊢ 1 st ↾ V × V -1 ∘ R -1 ∘ 1 st ↾ V × V -1 = 1 st ↾ V × V -1 ∘ R ∘ 1 st ↾ V × V
10 cnvco1 ⊢ 2 nd ↾ V × V -1 ∘ S -1 ∘ 2 nd ↾ V × V -1 = S -1 ∘ 2 nd ↾ V × V -1 ∘ 2 nd ↾ V × V
11 cnvco1 ⊢ S -1 ∘ 2 nd ↾ V × V -1 = 2 nd ↾ V × V -1 ∘ S
12 11 coeq1i ⊢ S -1 ∘ 2 nd ↾ V × V -1 ∘ 2 nd ↾ V × V = 2 nd ↾ V × V -1 ∘ S ∘ 2 nd ↾ V × V
13 coass ⊢ 2 nd ↾ V × V -1 ∘ S ∘ 2 nd ↾ V × V = 2 nd ↾ V × V -1 ∘ S ∘ 2 nd ↾ V × V
14 10 12 13 3eqtri ⊢ 2 nd ↾ V × V -1 ∘ S -1 ∘ 2 nd ↾ V × V -1 = 2 nd ↾ V × V -1 ∘ S ∘ 2 nd ↾ V × V
15 9 14 ineq12i ⊢ 1 st ↾ V × V -1 ∘ R -1 ∘ 1 st ↾ V × V -1 ∩ 2 nd ↾ V × V -1 ∘ S -1 ∘ 2 nd ↾ V × V -1 = 1 st ↾ V × V -1 ∘ R ∘ 1 st ↾ V × V ∩ 2 nd ↾ V × V -1 ∘ S ∘ 2 nd ↾ V × V
16 3 4 15 3eqtri ⊢ pprod R -1 S -1 -1 = 1 st ↾ V × V -1 ∘ R ∘ 1 st ↾ V × V ∩ 2 nd ↾ V × V -1 ∘ S ∘ 2 nd ↾ V × V
17 1 16 eqtr4i ⊢ pprod R S = pprod R -1 S -1 -1