Proof of Theorem clwlkclwwlkflem
Step | Hyp | Ref
| Expression |
1 | | fveq2 6774 |
. . . . . 6
⊢ (𝑤 = 𝑈 → (1st ‘𝑤) = (1st ‘𝑈)) |
2 | | clwlkclwwlkf.a |
. . . . . 6
⊢ 𝐴 = (1st ‘𝑈) |
3 | 1, 2 | eqtr4di 2796 |
. . . . 5
⊢ (𝑤 = 𝑈 → (1st ‘𝑤) = 𝐴) |
4 | 3 | fveq2d 6778 |
. . . 4
⊢ (𝑤 = 𝑈 → (♯‘(1st
‘𝑤)) =
(♯‘𝐴)) |
5 | 4 | breq2d 5086 |
. . 3
⊢ (𝑤 = 𝑈 → (1 ≤
(♯‘(1st ‘𝑤)) ↔ 1 ≤ (♯‘𝐴))) |
6 | | clwlkclwwlkf.c |
. . 3
⊢ 𝐶 = {𝑤 ∈ (ClWalks‘𝐺) ∣ 1 ≤
(♯‘(1st ‘𝑤))} |
7 | 5, 6 | elrab2 3627 |
. 2
⊢ (𝑈 ∈ 𝐶 ↔ (𝑈 ∈ (ClWalks‘𝐺) ∧ 1 ≤ (♯‘𝐴))) |
8 | | clwlkwlk 28143 |
. . . 4
⊢ (𝑈 ∈ (ClWalks‘𝐺) → 𝑈 ∈ (Walks‘𝐺)) |
9 | | wlkop 27995 |
. . . . 5
⊢ (𝑈 ∈ (Walks‘𝐺) → 𝑈 = 〈(1st ‘𝑈), (2nd ‘𝑈)〉) |
10 | | clwlkclwwlkf.b |
. . . . . . . 8
⊢ 𝐵 = (2nd ‘𝑈) |
11 | 2, 10 | opeq12i 4809 |
. . . . . . 7
⊢
〈𝐴, 𝐵〉 = 〈(1st
‘𝑈), (2nd
‘𝑈)〉 |
12 | 11 | eqeq2i 2751 |
. . . . . 6
⊢ (𝑈 = 〈𝐴, 𝐵〉 ↔ 𝑈 = 〈(1st ‘𝑈), (2nd ‘𝑈)〉) |
13 | | eleq1 2826 |
. . . . . . 7
⊢ (𝑈 = 〈𝐴, 𝐵〉 → (𝑈 ∈ (ClWalks‘𝐺) ↔ 〈𝐴, 𝐵〉 ∈ (ClWalks‘𝐺))) |
14 | | df-br 5075 |
. . . . . . . 8
⊢ (𝐴(ClWalks‘𝐺)𝐵 ↔ 〈𝐴, 𝐵〉 ∈ (ClWalks‘𝐺)) |
15 | | isclwlk 28141 |
. . . . . . . . 9
⊢ (𝐴(ClWalks‘𝐺)𝐵 ↔ (𝐴(Walks‘𝐺)𝐵 ∧ (𝐵‘0) = (𝐵‘(♯‘𝐴)))) |
16 | | wlkcl 27982 |
. . . . . . . . . . . . . . 15
⊢ (𝐴(Walks‘𝐺)𝐵 → (♯‘𝐴) ∈
ℕ0) |
17 | | elnnnn0c 12278 |
. . . . . . . . . . . . . . . 16
⊢
((♯‘𝐴)
∈ ℕ ↔ ((♯‘𝐴) ∈ ℕ0 ∧ 1 ≤
(♯‘𝐴))) |
18 | 17 | a1i 11 |
. . . . . . . . . . . . . . 15
⊢ (𝐴(Walks‘𝐺)𝐵 → ((♯‘𝐴) ∈ ℕ ↔
((♯‘𝐴) ∈
ℕ0 ∧ 1 ≤ (♯‘𝐴)))) |
19 | 16, 18 | mpbirand 704 |
. . . . . . . . . . . . . 14
⊢ (𝐴(Walks‘𝐺)𝐵 → ((♯‘𝐴) ∈ ℕ ↔ 1 ≤
(♯‘𝐴))) |
20 | 19 | bicomd 222 |
. . . . . . . . . . . . 13
⊢ (𝐴(Walks‘𝐺)𝐵 → (1 ≤ (♯‘𝐴) ↔ (♯‘𝐴) ∈
ℕ)) |
21 | 20 | adantr 481 |
. . . . . . . . . . . 12
⊢ ((𝐴(Walks‘𝐺)𝐵 ∧ (𝐵‘0) = (𝐵‘(♯‘𝐴))) → (1 ≤ (♯‘𝐴) ↔ (♯‘𝐴) ∈
ℕ)) |
22 | 21 | pm5.32i 575 |
. . . . . . . . . . 11
⊢ (((𝐴(Walks‘𝐺)𝐵 ∧ (𝐵‘0) = (𝐵‘(♯‘𝐴))) ∧ 1 ≤ (♯‘𝐴)) ↔ ((𝐴(Walks‘𝐺)𝐵 ∧ (𝐵‘0) = (𝐵‘(♯‘𝐴))) ∧ (♯‘𝐴) ∈ ℕ)) |
23 | | df-3an 1088 |
. . . . . . . . . . 11
⊢ ((𝐴(Walks‘𝐺)𝐵 ∧ (𝐵‘0) = (𝐵‘(♯‘𝐴)) ∧ (♯‘𝐴) ∈ ℕ) ↔ ((𝐴(Walks‘𝐺)𝐵 ∧ (𝐵‘0) = (𝐵‘(♯‘𝐴))) ∧ (♯‘𝐴) ∈ ℕ)) |
24 | 22, 23 | sylbb2 237 |
. . . . . . . . . 10
⊢ (((𝐴(Walks‘𝐺)𝐵 ∧ (𝐵‘0) = (𝐵‘(♯‘𝐴))) ∧ 1 ≤ (♯‘𝐴)) → (𝐴(Walks‘𝐺)𝐵 ∧ (𝐵‘0) = (𝐵‘(♯‘𝐴)) ∧ (♯‘𝐴) ∈ ℕ)) |
25 | 24 | ex 413 |
. . . . . . . . 9
⊢ ((𝐴(Walks‘𝐺)𝐵 ∧ (𝐵‘0) = (𝐵‘(♯‘𝐴))) → (1 ≤ (♯‘𝐴) → (𝐴(Walks‘𝐺)𝐵 ∧ (𝐵‘0) = (𝐵‘(♯‘𝐴)) ∧ (♯‘𝐴) ∈ ℕ))) |
26 | 15, 25 | sylbi 216 |
. . . . . . . 8
⊢ (𝐴(ClWalks‘𝐺)𝐵 → (1 ≤ (♯‘𝐴) → (𝐴(Walks‘𝐺)𝐵 ∧ (𝐵‘0) = (𝐵‘(♯‘𝐴)) ∧ (♯‘𝐴) ∈ ℕ))) |
27 | 14, 26 | sylbir 234 |
. . . . . . 7
⊢
(〈𝐴, 𝐵〉 ∈
(ClWalks‘𝐺) → (1
≤ (♯‘𝐴)
→ (𝐴(Walks‘𝐺)𝐵 ∧ (𝐵‘0) = (𝐵‘(♯‘𝐴)) ∧ (♯‘𝐴) ∈ ℕ))) |
28 | 13, 27 | syl6bi 252 |
. . . . . 6
⊢ (𝑈 = 〈𝐴, 𝐵〉 → (𝑈 ∈ (ClWalks‘𝐺) → (1 ≤ (♯‘𝐴) → (𝐴(Walks‘𝐺)𝐵 ∧ (𝐵‘0) = (𝐵‘(♯‘𝐴)) ∧ (♯‘𝐴) ∈ ℕ)))) |
29 | 12, 28 | sylbir 234 |
. . . . 5
⊢ (𝑈 = 〈(1st
‘𝑈), (2nd
‘𝑈)〉 →
(𝑈 ∈
(ClWalks‘𝐺) → (1
≤ (♯‘𝐴)
→ (𝐴(Walks‘𝐺)𝐵 ∧ (𝐵‘0) = (𝐵‘(♯‘𝐴)) ∧ (♯‘𝐴) ∈ ℕ)))) |
30 | 9, 29 | syl 17 |
. . . 4
⊢ (𝑈 ∈ (Walks‘𝐺) → (𝑈 ∈ (ClWalks‘𝐺) → (1 ≤ (♯‘𝐴) → (𝐴(Walks‘𝐺)𝐵 ∧ (𝐵‘0) = (𝐵‘(♯‘𝐴)) ∧ (♯‘𝐴) ∈ ℕ)))) |
31 | 8, 30 | mpcom 38 |
. . 3
⊢ (𝑈 ∈ (ClWalks‘𝐺) → (1 ≤
(♯‘𝐴) →
(𝐴(Walks‘𝐺)𝐵 ∧ (𝐵‘0) = (𝐵‘(♯‘𝐴)) ∧ (♯‘𝐴) ∈ ℕ))) |
32 | 31 | imp 407 |
. 2
⊢ ((𝑈 ∈ (ClWalks‘𝐺) ∧ 1 ≤
(♯‘𝐴)) →
(𝐴(Walks‘𝐺)𝐵 ∧ (𝐵‘0) = (𝐵‘(♯‘𝐴)) ∧ (♯‘𝐴) ∈ ℕ)) |
33 | 7, 32 | sylbi 216 |
1
⊢ (𝑈 ∈ 𝐶 → (𝐴(Walks‘𝐺)𝐵 ∧ (𝐵‘0) = (𝐵‘(♯‘𝐴)) ∧ (♯‘𝐴) ∈ ℕ)) |