Proof of Theorem clwlknf1oclwwlknlem1
| Step | Hyp | Ref
| Expression |
| 1 | | clwlkwlk 29757 |
. . 3
⊢ (𝐶 ∈ (ClWalks‘𝐺) → 𝐶 ∈ (Walks‘𝐺)) |
| 2 | | wlkcpr 29609 |
. . . 4
⊢ (𝐶 ∈ (Walks‘𝐺) ↔ (1st
‘𝐶)(Walks‘𝐺)(2nd ‘𝐶)) |
| 3 | | eqid 2735 |
. . . . . . . 8
⊢
(Vtx‘𝐺) =
(Vtx‘𝐺) |
| 4 | 3 | wlkpwrd 29597 |
. . . . . . 7
⊢
((1st ‘𝐶)(Walks‘𝐺)(2nd ‘𝐶) → (2nd ‘𝐶) ∈ Word (Vtx‘𝐺)) |
| 5 | | lencl 14551 |
. . . . . . . . 9
⊢
((2nd ‘𝐶) ∈ Word (Vtx‘𝐺) → (♯‘(2nd
‘𝐶)) ∈
ℕ0) |
| 6 | 4, 5 | syl 17 |
. . . . . . . 8
⊢
((1st ‘𝐶)(Walks‘𝐺)(2nd ‘𝐶) → (♯‘(2nd
‘𝐶)) ∈
ℕ0) |
| 7 | | wlklenvm1 29602 |
. . . . . . . . . . 11
⊢
((1st ‘𝐶)(Walks‘𝐺)(2nd ‘𝐶) → (♯‘(1st
‘𝐶)) =
((♯‘(2nd ‘𝐶)) − 1)) |
| 8 | 7 | breq2d 5131 |
. . . . . . . . . 10
⊢
((1st ‘𝐶)(Walks‘𝐺)(2nd ‘𝐶) → (1 ≤
(♯‘(1st ‘𝐶)) ↔ 1 ≤
((♯‘(2nd ‘𝐶)) − 1))) |
| 9 | | 1red 11236 |
. . . . . . . . . . . . 13
⊢
((♯‘(2nd ‘𝐶)) ∈ ℕ0 → 1
∈ ℝ) |
| 10 | | nn0re 12510 |
. . . . . . . . . . . . 13
⊢
((♯‘(2nd ‘𝐶)) ∈ ℕ0 →
(♯‘(2nd ‘𝐶)) ∈ ℝ) |
| 11 | 9, 9, 10 | leaddsub2d 11839 |
. . . . . . . . . . . 12
⊢
((♯‘(2nd ‘𝐶)) ∈ ℕ0 → ((1 +
1) ≤ (♯‘(2nd ‘𝐶)) ↔ 1 ≤
((♯‘(2nd ‘𝐶)) − 1))) |
| 12 | | 1p1e2 12365 |
. . . . . . . . . . . . . 14
⊢ (1 + 1) =
2 |
| 13 | 12 | breq1i 5126 |
. . . . . . . . . . . . 13
⊢ ((1 + 1)
≤ (♯‘(2nd ‘𝐶)) ↔ 2 ≤
(♯‘(2nd ‘𝐶))) |
| 14 | 13 | biimpi 216 |
. . . . . . . . . . . 12
⊢ ((1 + 1)
≤ (♯‘(2nd ‘𝐶)) → 2 ≤
(♯‘(2nd ‘𝐶))) |
| 15 | 11, 14 | biimtrrdi 254 |
. . . . . . . . . . 11
⊢
((♯‘(2nd ‘𝐶)) ∈ ℕ0 → (1 ≤
((♯‘(2nd ‘𝐶)) − 1) → 2 ≤
(♯‘(2nd ‘𝐶)))) |
| 16 | 4, 5, 15 | 3syl 18 |
. . . . . . . . . 10
⊢
((1st ‘𝐶)(Walks‘𝐺)(2nd ‘𝐶) → (1 ≤
((♯‘(2nd ‘𝐶)) − 1) → 2 ≤
(♯‘(2nd ‘𝐶)))) |
| 17 | 8, 16 | sylbid 240 |
. . . . . . . . 9
⊢
((1st ‘𝐶)(Walks‘𝐺)(2nd ‘𝐶) → (1 ≤
(♯‘(1st ‘𝐶)) → 2 ≤
(♯‘(2nd ‘𝐶)))) |
| 18 | 17 | imp 406 |
. . . . . . . 8
⊢
(((1st ‘𝐶)(Walks‘𝐺)(2nd ‘𝐶) ∧ 1 ≤
(♯‘(1st ‘𝐶))) → 2 ≤
(♯‘(2nd ‘𝐶))) |
| 19 | | ige2m1fz 13634 |
. . . . . . . 8
⊢
(((♯‘(2nd ‘𝐶)) ∈ ℕ0 ∧ 2 ≤
(♯‘(2nd ‘𝐶))) → ((♯‘(2nd
‘𝐶)) − 1)
∈ (0...(♯‘(2nd ‘𝐶)))) |
| 20 | 6, 18, 19 | syl2an2r 685 |
. . . . . . 7
⊢
(((1st ‘𝐶)(Walks‘𝐺)(2nd ‘𝐶) ∧ 1 ≤
(♯‘(1st ‘𝐶))) → ((♯‘(2nd
‘𝐶)) − 1)
∈ (0...(♯‘(2nd ‘𝐶)))) |
| 21 | | pfxlen 14701 |
. . . . . . 7
⊢
(((2nd ‘𝐶) ∈ Word (Vtx‘𝐺) ∧ ((♯‘(2nd
‘𝐶)) − 1)
∈ (0...(♯‘(2nd ‘𝐶)))) → (♯‘((2nd
‘𝐶) prefix
((♯‘(2nd ‘𝐶)) − 1))) =
((♯‘(2nd ‘𝐶)) − 1)) |
| 22 | 4, 20, 21 | syl2an2r 685 |
. . . . . 6
⊢
(((1st ‘𝐶)(Walks‘𝐺)(2nd ‘𝐶) ∧ 1 ≤
(♯‘(1st ‘𝐶))) → (♯‘((2nd
‘𝐶) prefix
((♯‘(2nd ‘𝐶)) − 1))) =
((♯‘(2nd ‘𝐶)) − 1)) |
| 23 | 7 | eqcomd 2741 |
. . . . . . 7
⊢
((1st ‘𝐶)(Walks‘𝐺)(2nd ‘𝐶) → ((♯‘(2nd
‘𝐶)) − 1) =
(♯‘(1st ‘𝐶))) |
| 24 | 23 | adantr 480 |
. . . . . 6
⊢
(((1st ‘𝐶)(Walks‘𝐺)(2nd ‘𝐶) ∧ 1 ≤
(♯‘(1st ‘𝐶))) → ((♯‘(2nd
‘𝐶)) − 1) =
(♯‘(1st ‘𝐶))) |
| 25 | 22, 24 | eqtrd 2770 |
. . . . 5
⊢
(((1st ‘𝐶)(Walks‘𝐺)(2nd ‘𝐶) ∧ 1 ≤
(♯‘(1st ‘𝐶))) → (♯‘((2nd
‘𝐶) prefix
((♯‘(2nd ‘𝐶)) − 1))) =
(♯‘(1st ‘𝐶))) |
| 26 | 25 | ex 412 |
. . . 4
⊢
((1st ‘𝐶)(Walks‘𝐺)(2nd ‘𝐶) → (1 ≤
(♯‘(1st ‘𝐶)) → (♯‘((2nd
‘𝐶) prefix
((♯‘(2nd ‘𝐶)) − 1))) =
(♯‘(1st ‘𝐶)))) |
| 27 | 2, 26 | sylbi 217 |
. . 3
⊢ (𝐶 ∈ (Walks‘𝐺) → (1 ≤
(♯‘(1st ‘𝐶)) → (♯‘((2nd
‘𝐶) prefix
((♯‘(2nd ‘𝐶)) − 1))) =
(♯‘(1st ‘𝐶)))) |
| 28 | 1, 27 | syl 17 |
. 2
⊢ (𝐶 ∈ (ClWalks‘𝐺) → (1 ≤
(♯‘(1st ‘𝐶)) → (♯‘((2nd
‘𝐶) prefix
((♯‘(2nd ‘𝐶)) − 1))) =
(♯‘(1st ‘𝐶)))) |
| 29 | 28 | imp 406 |
1
⊢ ((𝐶 ∈ (ClWalks‘𝐺) ∧ 1 ≤
(♯‘(1st ‘𝐶))) → (♯‘((2nd
‘𝐶) prefix
((♯‘(2nd ‘𝐶)) − 1))) =
(♯‘(1st ‘𝐶))) |