Metamath Proof Explorer


Theorem cotrcltrcl

Description: The transitive closure is idempotent. (Contributed by RP, 16-Jun-2020)

Ref Expression
Assertion cotrcltrcl t+t+=t+

Proof

Step Hyp Ref Expression
1 dftrcl3 t+=aViari
2 dftrcl3 t+=bVjbrj
3 dftrcl3 t+=cVkcrk
4 nnex V
5 unidm =
6 5 eqcomi =
7 1ex 1V
8 oveq2 i=1jdrjri=jdrjr1
9 7 8 iunxsn i1jdrjri=jdrjr1
10 ovex drjV
11 4 10 iunex jdrjV
12 relexp1g jdrjVjdrjr1=jdrj
13 11 12 ax-mp jdrjr1=jdrj
14 oveq2 j=kdrj=drk
15 14 cbviunv jdrj=kdrk
16 13 15 eqtri jdrjr1=kdrk
17 9 16 eqtri i1jdrjri=kdrk
18 17 eqcomi kdrk=i1jdrjri
19 1nn 1
20 snssi 11
21 iunss1 1i1jdrjriijdrjri
22 19 20 21 mp2b i1jdrjriijdrjri
23 18 22 eqsstri kdrkijdrjri
24 iunss ijdrjrikdrkijdrjrikdrk
25 oveq2 x=1jdrjrx=jdrjr1
26 25 sseq1d x=1jdrjrxkdrkjdrjr1kdrk
27 oveq2 x=yjdrjrx=jdrjry
28 27 sseq1d x=yjdrjrxkdrkjdrjrykdrk
29 oveq2 x=y+1jdrjrx=jdrjry+1
30 29 sseq1d x=y+1jdrjrxkdrkjdrjry+1kdrk
31 oveq2 x=ijdrjrx=jdrjri
32 31 sseq1d x=ijdrjrxkdrkjdrjrikdrk
33 16 eqimssi jdrjr1kdrk
34 simpl yjdrjrykdrky
35 relexpsucnnr jdrjVyjdrjry+1=jdrjryjdrj
36 11 34 35 sylancr yjdrjrykdrkjdrjry+1=jdrjryjdrj
37 coss1 jdrjrykdrkjdrjryjdrjkdrkjdrj
38 37 adantl yjdrjrykdrkjdrjryjdrjkdrkjdrj
39 15 coeq2i kdrkjdrj=kdrkkdrk
40 trclfvcotrg t+dt+dt+d
41 oveq1 c=dcrk=drk
42 41 iuneq2d c=dkcrk=kdrk
43 ovex drkV
44 4 43 iunex kdrkV
45 42 3 44 fvmpt dVt+d=kdrk
46 45 elv t+d=kdrk
47 46 46 coeq12i t+dt+d=kdrkkdrk
48 40 47 46 3sstr3i kdrkkdrkkdrk
49 39 48 eqsstri kdrkjdrjkdrk
50 38 49 sstrdi yjdrjrykdrkjdrjryjdrjkdrk
51 36 50 eqsstrd yjdrjrykdrkjdrjry+1kdrk
52 51 ex yjdrjrykdrkjdrjry+1kdrk
53 26 28 30 32 33 52 nnind ijdrjrikdrk
54 24 53 mprgbir ijdrjrikdrk
55 iuneq1 =kdrk=kdrk
56 6 55 ax-mp kdrk=kdrk
57 54 56 sseqtri ijdrjrikdrk
58 1 2 3 4 4 6 23 23 57 comptiunov2i t+t+=t+