Metamath Proof Explorer


Theorem cycpm2tr

Description: A cyclic permutation of 2 elements is a transposition. (Contributed by Thierry Arnoux, 24-Sep-2023)

Ref Expression
Hypotheses cycpm2.c 𝐶 = ( toCyc ‘ 𝐷 )
cycpm2.d ( 𝜑𝐷𝑉 )
cycpm2.i ( 𝜑𝐼𝐷 )
cycpm2.j ( 𝜑𝐽𝐷 )
cycpm2.1 ( 𝜑𝐼𝐽 )
cycpm2tr.t 𝑇 = ( pmTrsp ‘ 𝐷 )
Assertion cycpm2tr ( 𝜑 → ( 𝐶 ‘ ⟨“ 𝐼 𝐽 ”⟩ ) = ( 𝑇 ‘ { 𝐼 , 𝐽 } ) )

Proof

Step Hyp Ref Expression
1 cycpm2.c 𝐶 = ( toCyc ‘ 𝐷 )
2 cycpm2.d ( 𝜑𝐷𝑉 )
3 cycpm2.i ( 𝜑𝐼𝐷 )
4 cycpm2.j ( 𝜑𝐽𝐷 )
5 cycpm2.1 ( 𝜑𝐼𝐽 )
6 cycpm2tr.t 𝑇 = ( pmTrsp ‘ 𝐷 )
7 partfun ( 𝑥𝐷 ↦ if ( 𝑥 ∈ { 𝐼 , 𝐽 } , ( { 𝐼 , 𝐽 } ∖ { 𝑥 } ) , 𝑥 ) ) = ( ( 𝑥 ∈ ( 𝐷 ∩ { 𝐼 , 𝐽 } ) ↦ ( { 𝐼 , 𝐽 } ∖ { 𝑥 } ) ) ∪ ( 𝑥 ∈ ( 𝐷 ∖ { 𝐼 , 𝐽 } ) ↦ 𝑥 ) )
8 7 a1i ( 𝜑 → ( 𝑥𝐷 ↦ if ( 𝑥 ∈ { 𝐼 , 𝐽 } , ( { 𝐼 , 𝐽 } ∖ { 𝑥 } ) , 𝑥 ) ) = ( ( 𝑥 ∈ ( 𝐷 ∩ { 𝐼 , 𝐽 } ) ↦ ( { 𝐼 , 𝐽 } ∖ { 𝑥 } ) ) ∪ ( 𝑥 ∈ ( 𝐷 ∖ { 𝐼 , 𝐽 } ) ↦ 𝑥 ) ) )
9 cshw1s2 ( ( 𝐼𝐷𝐽𝐷 ) → ( ⟨“ 𝐼 𝐽 ”⟩ cyclShift 1 ) = ⟨“ 𝐽 𝐼 ”⟩ )
10 3 4 9 syl2anc ( 𝜑 → ( ⟨“ 𝐼 𝐽 ”⟩ cyclShift 1 ) = ⟨“ 𝐽 𝐼 ”⟩ )
11 10 coeq1d ( 𝜑 → ( ( ⟨“ 𝐼 𝐽 ”⟩ cyclShift 1 ) ∘ ⟨“ 𝐼 𝐽 ”⟩ ) = ( ⟨“ 𝐽 𝐼 ”⟩ ∘ ⟨“ 𝐼 𝐽 ”⟩ ) )
12 0nn0 0 ∈ ℕ0
13 12 a1i ( 𝜑 → 0 ∈ ℕ0 )
14 1nn0 1 ∈ ℕ0
15 14 a1i ( 𝜑 → 1 ∈ ℕ0 )
16 0ne1 0 ≠ 1
17 16 a1i ( 𝜑 → 0 ≠ 1 )
18 13 4 15 3 17 3 4 5 coprprop ( 𝜑 → ( { ⟨ 0 , 𝐽 ⟩ , ⟨ 1 , 𝐼 ⟩ } ∘ { ⟨ 𝐼 , 0 ⟩ , ⟨ 𝐽 , 1 ⟩ } ) = { ⟨ 𝐼 , 𝐽 ⟩ , ⟨ 𝐽 , 𝐼 ⟩ } )
19 s2prop ( ( 𝐽𝐷𝐼𝐷 ) → ⟨“ 𝐽 𝐼 ”⟩ = { ⟨ 0 , 𝐽 ⟩ , ⟨ 1 , 𝐼 ⟩ } )
20 4 3 19 syl2anc ( 𝜑 → ⟨“ 𝐽 𝐼 ”⟩ = { ⟨ 0 , 𝐽 ⟩ , ⟨ 1 , 𝐼 ⟩ } )
21 s2prop ( ( 𝐼𝐷𝐽𝐷 ) → ⟨“ 𝐼 𝐽 ”⟩ = { ⟨ 0 , 𝐼 ⟩ , ⟨ 1 , 𝐽 ⟩ } )
22 3 4 21 syl2anc ( 𝜑 → ⟨“ 𝐼 𝐽 ”⟩ = { ⟨ 0 , 𝐼 ⟩ , ⟨ 1 , 𝐽 ⟩ } )
23 22 cnveqd ( 𝜑 ⟨“ 𝐼 𝐽 ”⟩ = { ⟨ 0 , 𝐼 ⟩ , ⟨ 1 , 𝐽 ⟩ } )
24 cnvprop ( ( ( 0 ∈ ℕ0𝐼𝐷 ) ∧ ( 1 ∈ ℕ0𝐽𝐷 ) ) → { ⟨ 0 , 𝐼 ⟩ , ⟨ 1 , 𝐽 ⟩ } = { ⟨ 𝐼 , 0 ⟩ , ⟨ 𝐽 , 1 ⟩ } )
25 13 3 15 4 24 syl22anc ( 𝜑 { ⟨ 0 , 𝐼 ⟩ , ⟨ 1 , 𝐽 ⟩ } = { ⟨ 𝐼 , 0 ⟩ , ⟨ 𝐽 , 1 ⟩ } )
26 23 25 eqtrd ( 𝜑 ⟨“ 𝐼 𝐽 ”⟩ = { ⟨ 𝐼 , 0 ⟩ , ⟨ 𝐽 , 1 ⟩ } )
27 20 26 coeq12d ( 𝜑 → ( ⟨“ 𝐽 𝐼 ”⟩ ∘ ⟨“ 𝐼 𝐽 ”⟩ ) = ( { ⟨ 0 , 𝐽 ⟩ , ⟨ 1 , 𝐼 ⟩ } ∘ { ⟨ 𝐼 , 0 ⟩ , ⟨ 𝐽 , 1 ⟩ } ) )
28 3 4 4 3 5 mptprop ( 𝜑 → { ⟨ 𝐼 , 𝐽 ⟩ , ⟨ 𝐽 , 𝐼 ⟩ } = ( 𝑥 ∈ { 𝐼 , 𝐽 } ↦ if ( 𝑥 = 𝐼 , 𝐽 , 𝐼 ) ) )
29 incom ( { 𝐼 , 𝐽 } ∩ 𝐷 ) = ( 𝐷 ∩ { 𝐼 , 𝐽 } )
30 3 4 prssd ( 𝜑 → { 𝐼 , 𝐽 } ⊆ 𝐷 )
31 df-ss ( { 𝐼 , 𝐽 } ⊆ 𝐷 ↔ ( { 𝐼 , 𝐽 } ∩ 𝐷 ) = { 𝐼 , 𝐽 } )
32 30 31 sylib ( 𝜑 → ( { 𝐼 , 𝐽 } ∩ 𝐷 ) = { 𝐼 , 𝐽 } )
33 29 32 syl5reqr ( 𝜑 → { 𝐼 , 𝐽 } = ( 𝐷 ∩ { 𝐼 , 𝐽 } ) )
34 simpr ( ( ( 𝜑𝑥 ∈ { 𝐼 , 𝐽 } ) ∧ 𝑥 = 𝐼 ) → 𝑥 = 𝐼 )
35 34 sneqd ( ( ( 𝜑𝑥 ∈ { 𝐼 , 𝐽 } ) ∧ 𝑥 = 𝐼 ) → { 𝑥 } = { 𝐼 } )
36 35 difeq2d ( ( ( 𝜑𝑥 ∈ { 𝐼 , 𝐽 } ) ∧ 𝑥 = 𝐼 ) → ( { 𝐼 , 𝐽 } ∖ { 𝑥 } ) = ( { 𝐼 , 𝐽 } ∖ { 𝐼 } ) )
37 36 unieqd ( ( ( 𝜑𝑥 ∈ { 𝐼 , 𝐽 } ) ∧ 𝑥 = 𝐼 ) → ( { 𝐼 , 𝐽 } ∖ { 𝑥 } ) = ( { 𝐼 , 𝐽 } ∖ { 𝐼 } ) )
38 difprsn1 ( 𝐼𝐽 → ( { 𝐼 , 𝐽 } ∖ { 𝐼 } ) = { 𝐽 } )
39 38 unieqd ( 𝐼𝐽 ( { 𝐼 , 𝐽 } ∖ { 𝐼 } ) = { 𝐽 } )
40 5 39 syl ( 𝜑 ( { 𝐼 , 𝐽 } ∖ { 𝐼 } ) = { 𝐽 } )
41 unisng ( 𝐽𝐷 { 𝐽 } = 𝐽 )
42 4 41 syl ( 𝜑 { 𝐽 } = 𝐽 )
43 40 42 eqtrd ( 𝜑 ( { 𝐼 , 𝐽 } ∖ { 𝐼 } ) = 𝐽 )
44 43 ad2antrr ( ( ( 𝜑𝑥 ∈ { 𝐼 , 𝐽 } ) ∧ 𝑥 = 𝐼 ) → ( { 𝐼 , 𝐽 } ∖ { 𝐼 } ) = 𝐽 )
45 37 44 eqtr2d ( ( ( 𝜑𝑥 ∈ { 𝐼 , 𝐽 } ) ∧ 𝑥 = 𝐼 ) → 𝐽 = ( { 𝐼 , 𝐽 } ∖ { 𝑥 } ) )
46 vex 𝑥 ∈ V
47 46 elpr ( 𝑥 ∈ { 𝐼 , 𝐽 } ↔ ( 𝑥 = 𝐼𝑥 = 𝐽 ) )
48 df-or ( ( 𝑥 = 𝐼𝑥 = 𝐽 ) ↔ ( ¬ 𝑥 = 𝐼𝑥 = 𝐽 ) )
49 47 48 sylbb ( 𝑥 ∈ { 𝐼 , 𝐽 } → ( ¬ 𝑥 = 𝐼𝑥 = 𝐽 ) )
50 49 imp ( ( 𝑥 ∈ { 𝐼 , 𝐽 } ∧ ¬ 𝑥 = 𝐼 ) → 𝑥 = 𝐽 )
51 50 adantll ( ( ( 𝜑𝑥 ∈ { 𝐼 , 𝐽 } ) ∧ ¬ 𝑥 = 𝐼 ) → 𝑥 = 𝐽 )
52 51 sneqd ( ( ( 𝜑𝑥 ∈ { 𝐼 , 𝐽 } ) ∧ ¬ 𝑥 = 𝐼 ) → { 𝑥 } = { 𝐽 } )
53 52 difeq2d ( ( ( 𝜑𝑥 ∈ { 𝐼 , 𝐽 } ) ∧ ¬ 𝑥 = 𝐼 ) → ( { 𝐼 , 𝐽 } ∖ { 𝑥 } ) = ( { 𝐼 , 𝐽 } ∖ { 𝐽 } ) )
54 53 unieqd ( ( ( 𝜑𝑥 ∈ { 𝐼 , 𝐽 } ) ∧ ¬ 𝑥 = 𝐼 ) → ( { 𝐼 , 𝐽 } ∖ { 𝑥 } ) = ( { 𝐼 , 𝐽 } ∖ { 𝐽 } ) )
55 difprsn2 ( 𝐼𝐽 → ( { 𝐼 , 𝐽 } ∖ { 𝐽 } ) = { 𝐼 } )
56 55 unieqd ( 𝐼𝐽 ( { 𝐼 , 𝐽 } ∖ { 𝐽 } ) = { 𝐼 } )
57 5 56 syl ( 𝜑 ( { 𝐼 , 𝐽 } ∖ { 𝐽 } ) = { 𝐼 } )
58 unisng ( 𝐼𝐷 { 𝐼 } = 𝐼 )
59 3 58 syl ( 𝜑 { 𝐼 } = 𝐼 )
60 57 59 eqtrd ( 𝜑 ( { 𝐼 , 𝐽 } ∖ { 𝐽 } ) = 𝐼 )
61 60 ad2antrr ( ( ( 𝜑𝑥 ∈ { 𝐼 , 𝐽 } ) ∧ ¬ 𝑥 = 𝐼 ) → ( { 𝐼 , 𝐽 } ∖ { 𝐽 } ) = 𝐼 )
62 54 61 eqtr2d ( ( ( 𝜑𝑥 ∈ { 𝐼 , 𝐽 } ) ∧ ¬ 𝑥 = 𝐼 ) → 𝐼 = ( { 𝐼 , 𝐽 } ∖ { 𝑥 } ) )
63 45 62 ifeqda ( ( 𝜑𝑥 ∈ { 𝐼 , 𝐽 } ) → if ( 𝑥 = 𝐼 , 𝐽 , 𝐼 ) = ( { 𝐼 , 𝐽 } ∖ { 𝑥 } ) )
64 33 63 mpteq12dva ( 𝜑 → ( 𝑥 ∈ { 𝐼 , 𝐽 } ↦ if ( 𝑥 = 𝐼 , 𝐽 , 𝐼 ) ) = ( 𝑥 ∈ ( 𝐷 ∩ { 𝐼 , 𝐽 } ) ↦ ( { 𝐼 , 𝐽 } ∖ { 𝑥 } ) ) )
65 28 64 eqtr2d ( 𝜑 → ( 𝑥 ∈ ( 𝐷 ∩ { 𝐼 , 𝐽 } ) ↦ ( { 𝐼 , 𝐽 } ∖ { 𝑥 } ) ) = { ⟨ 𝐼 , 𝐽 ⟩ , ⟨ 𝐽 , 𝐼 ⟩ } )
66 18 27 65 3eqtr4d ( 𝜑 → ( ⟨“ 𝐽 𝐼 ”⟩ ∘ ⟨“ 𝐼 𝐽 ”⟩ ) = ( 𝑥 ∈ ( 𝐷 ∩ { 𝐼 , 𝐽 } ) ↦ ( { 𝐼 , 𝐽 } ∖ { 𝑥 } ) ) )
67 11 66 eqtrd ( 𝜑 → ( ( ⟨“ 𝐼 𝐽 ”⟩ cyclShift 1 ) ∘ ⟨“ 𝐼 𝐽 ”⟩ ) = ( 𝑥 ∈ ( 𝐷 ∩ { 𝐼 , 𝐽 } ) ↦ ( { 𝐼 , 𝐽 } ∖ { 𝑥 } ) ) )
68 3 4 s2rn ( 𝜑 → ran ⟨“ 𝐼 𝐽 ”⟩ = { 𝐼 , 𝐽 } )
69 68 difeq2d ( 𝜑 → ( 𝐷 ∖ ran ⟨“ 𝐼 𝐽 ”⟩ ) = ( 𝐷 ∖ { 𝐼 , 𝐽 } ) )
70 69 reseq2d ( 𝜑 → ( I ↾ ( 𝐷 ∖ ran ⟨“ 𝐼 𝐽 ”⟩ ) ) = ( I ↾ ( 𝐷 ∖ { 𝐼 , 𝐽 } ) ) )
71 mptresid ( I ↾ ( 𝐷 ∖ { 𝐼 , 𝐽 } ) ) = ( 𝑥 ∈ ( 𝐷 ∖ { 𝐼 , 𝐽 } ) ↦ 𝑥 )
72 70 71 eqtrdi ( 𝜑 → ( I ↾ ( 𝐷 ∖ ran ⟨“ 𝐼 𝐽 ”⟩ ) ) = ( 𝑥 ∈ ( 𝐷 ∖ { 𝐼 , 𝐽 } ) ↦ 𝑥 ) )
73 67 72 uneq12d ( 𝜑 → ( ( ( ⟨“ 𝐼 𝐽 ”⟩ cyclShift 1 ) ∘ ⟨“ 𝐼 𝐽 ”⟩ ) ∪ ( I ↾ ( 𝐷 ∖ ran ⟨“ 𝐼 𝐽 ”⟩ ) ) ) = ( ( 𝑥 ∈ ( 𝐷 ∩ { 𝐼 , 𝐽 } ) ↦ ( { 𝐼 , 𝐽 } ∖ { 𝑥 } ) ) ∪ ( 𝑥 ∈ ( 𝐷 ∖ { 𝐼 , 𝐽 } ) ↦ 𝑥 ) ) )
74 uncom ( ( ( ⟨“ 𝐼 𝐽 ”⟩ cyclShift 1 ) ∘ ⟨“ 𝐼 𝐽 ”⟩ ) ∪ ( I ↾ ( 𝐷 ∖ ran ⟨“ 𝐼 𝐽 ”⟩ ) ) ) = ( ( I ↾ ( 𝐷 ∖ ran ⟨“ 𝐼 𝐽 ”⟩ ) ) ∪ ( ( ⟨“ 𝐼 𝐽 ”⟩ cyclShift 1 ) ∘ ⟨“ 𝐼 𝐽 ”⟩ ) )
75 74 a1i ( 𝜑 → ( ( ( ⟨“ 𝐼 𝐽 ”⟩ cyclShift 1 ) ∘ ⟨“ 𝐼 𝐽 ”⟩ ) ∪ ( I ↾ ( 𝐷 ∖ ran ⟨“ 𝐼 𝐽 ”⟩ ) ) ) = ( ( I ↾ ( 𝐷 ∖ ran ⟨“ 𝐼 𝐽 ”⟩ ) ) ∪ ( ( ⟨“ 𝐼 𝐽 ”⟩ cyclShift 1 ) ∘ ⟨“ 𝐼 𝐽 ”⟩ ) ) )
76 8 73 75 3eqtr2rd ( 𝜑 → ( ( I ↾ ( 𝐷 ∖ ran ⟨“ 𝐼 𝐽 ”⟩ ) ) ∪ ( ( ⟨“ 𝐼 𝐽 ”⟩ cyclShift 1 ) ∘ ⟨“ 𝐼 𝐽 ”⟩ ) ) = ( 𝑥𝐷 ↦ if ( 𝑥 ∈ { 𝐼 , 𝐽 } , ( { 𝐼 , 𝐽 } ∖ { 𝑥 } ) , 𝑥 ) ) )
77 3 4 s2cld ( 𝜑 → ⟨“ 𝐼 𝐽 ”⟩ ∈ Word 𝐷 )
78 3 4 5 s2f1 ( 𝜑 → ⟨“ 𝐼 𝐽 ”⟩ : dom ⟨“ 𝐼 𝐽 ”⟩ –1-1𝐷 )
79 1 2 77 78 tocycfv ( 𝜑 → ( 𝐶 ‘ ⟨“ 𝐼 𝐽 ”⟩ ) = ( ( I ↾ ( 𝐷 ∖ ran ⟨“ 𝐼 𝐽 ”⟩ ) ) ∪ ( ( ⟨“ 𝐼 𝐽 ”⟩ cyclShift 1 ) ∘ ⟨“ 𝐼 𝐽 ”⟩ ) ) )
80 pr2nelem ( ( 𝐼𝐷𝐽𝐷𝐼𝐽 ) → { 𝐼 , 𝐽 } ≈ 2o )
81 3 4 5 80 syl3anc ( 𝜑 → { 𝐼 , 𝐽 } ≈ 2o )
82 6 pmtrval ( ( 𝐷𝑉 ∧ { 𝐼 , 𝐽 } ⊆ 𝐷 ∧ { 𝐼 , 𝐽 } ≈ 2o ) → ( 𝑇 ‘ { 𝐼 , 𝐽 } ) = ( 𝑥𝐷 ↦ if ( 𝑥 ∈ { 𝐼 , 𝐽 } , ( { 𝐼 , 𝐽 } ∖ { 𝑥 } ) , 𝑥 ) ) )
83 2 30 81 82 syl3anc ( 𝜑 → ( 𝑇 ‘ { 𝐼 , 𝐽 } ) = ( 𝑥𝐷 ↦ if ( 𝑥 ∈ { 𝐼 , 𝐽 } , ( { 𝐼 , 𝐽 } ∖ { 𝑥 } ) , 𝑥 ) ) )
84 76 79 83 3eqtr4d ( 𝜑 → ( 𝐶 ‘ ⟨“ 𝐼 𝐽 ”⟩ ) = ( 𝑇 ‘ { 𝐼 , 𝐽 } ) )