Metamath Proof Explorer


Theorem trlcocnv

Description: Swap the arguments of the trace of a composition with converse. (Contributed by NM, 1-Jul-2013)

Ref Expression
Hypotheses trlcocnv.h 𝐻 = ( LHyp ‘ 𝐾 )
trlcocnv.t 𝑇 = ( ( LTrn ‘ 𝐾 ) ‘ 𝑊 )
trlcocnv.r 𝑅 = ( ( trL ‘ 𝐾 ) ‘ 𝑊 )
Assertion trlcocnv ( ( ( 𝐾 ∈ HL ∧ 𝑊𝐻 ) ∧ 𝐹𝑇𝐺𝑇 ) → ( 𝑅 ‘ ( 𝐹 𝐺 ) ) = ( 𝑅 ‘ ( 𝐺 𝐹 ) ) )

Proof

Step Hyp Ref Expression
1 trlcocnv.h 𝐻 = ( LHyp ‘ 𝐾 )
2 trlcocnv.t 𝑇 = ( ( LTrn ‘ 𝐾 ) ‘ 𝑊 )
3 trlcocnv.r 𝑅 = ( ( trL ‘ 𝐾 ) ‘ 𝑊 )
4 simp1 ( ( ( 𝐾 ∈ HL ∧ 𝑊𝐻 ) ∧ 𝐹𝑇𝐺𝑇 ) → ( 𝐾 ∈ HL ∧ 𝑊𝐻 ) )
5 1 2 ltrncnv ( ( ( 𝐾 ∈ HL ∧ 𝑊𝐻 ) ∧ 𝐺𝑇 ) → 𝐺𝑇 )
6 5 3adant2 ( ( ( 𝐾 ∈ HL ∧ 𝑊𝐻 ) ∧ 𝐹𝑇𝐺𝑇 ) → 𝐺𝑇 )
7 1 2 ltrnco ( ( ( 𝐾 ∈ HL ∧ 𝑊𝐻 ) ∧ 𝐹𝑇 𝐺𝑇 ) → ( 𝐹 𝐺 ) ∈ 𝑇 )
8 6 7 syld3an3 ( ( ( 𝐾 ∈ HL ∧ 𝑊𝐻 ) ∧ 𝐹𝑇𝐺𝑇 ) → ( 𝐹 𝐺 ) ∈ 𝑇 )
9 1 2 3 trlcnv ( ( ( 𝐾 ∈ HL ∧ 𝑊𝐻 ) ∧ ( 𝐹 𝐺 ) ∈ 𝑇 ) → ( 𝑅 ( 𝐹 𝐺 ) ) = ( 𝑅 ‘ ( 𝐹 𝐺 ) ) )
10 4 8 9 syl2anc ( ( ( 𝐾 ∈ HL ∧ 𝑊𝐻 ) ∧ 𝐹𝑇𝐺𝑇 ) → ( 𝑅 ( 𝐹 𝐺 ) ) = ( 𝑅 ‘ ( 𝐹 𝐺 ) ) )
11 cnvco ( 𝐹 𝐺 ) = ( 𝐺 𝐹 )
12 cocnvcnv1 ( 𝐺 𝐹 ) = ( 𝐺 𝐹 )
13 11 12 eqtri ( 𝐹 𝐺 ) = ( 𝐺 𝐹 )
14 13 fveq2i ( 𝑅 ( 𝐹 𝐺 ) ) = ( 𝑅 ‘ ( 𝐺 𝐹 ) )
15 10 14 eqtr3di ( ( ( 𝐾 ∈ HL ∧ 𝑊𝐻 ) ∧ 𝐹𝑇𝐺𝑇 ) → ( 𝑅 ‘ ( 𝐹 𝐺 ) ) = ( 𝑅 ‘ ( 𝐺 𝐹 ) ) )