Step | Hyp | Ref
| Expression |
1 | | 1nn0 12179 |
. . . . . . . . 9
⊢ 1 ∈
ℕ0 |
2 | | iswwlksn 28104 |
. . . . . . . . 9
⊢ (1 ∈
ℕ0 → (𝑤 ∈ (1 WWalksN 𝐺) ↔ (𝑤 ∈ (WWalks‘𝐺) ∧ (♯‘𝑤) = (1 + 1)))) |
3 | 1, 2 | ax-mp 5 |
. . . . . . . 8
⊢ (𝑤 ∈ (1 WWalksN 𝐺) ↔ (𝑤 ∈ (WWalks‘𝐺) ∧ (♯‘𝑤) = (1 + 1))) |
4 | | rusgrnumwwlkl1.v |
. . . . . . . . . 10
⊢ 𝑉 = (Vtx‘𝐺) |
5 | | eqid 2738 |
. . . . . . . . . 10
⊢
(Edg‘𝐺) =
(Edg‘𝐺) |
6 | 4, 5 | iswwlks 28102 |
. . . . . . . . 9
⊢ (𝑤 ∈ (WWalks‘𝐺) ↔ (𝑤 ≠ ∅ ∧ 𝑤 ∈ Word 𝑉 ∧ ∀𝑖 ∈ (0..^((♯‘𝑤) − 1)){(𝑤‘𝑖), (𝑤‘(𝑖 + 1))} ∈ (Edg‘𝐺))) |
7 | 6 | anbi1i 623 |
. . . . . . . 8
⊢ ((𝑤 ∈ (WWalks‘𝐺) ∧ (♯‘𝑤) = (1 + 1)) ↔ ((𝑤 ≠ ∅ ∧ 𝑤 ∈ Word 𝑉 ∧ ∀𝑖 ∈ (0..^((♯‘𝑤) − 1)){(𝑤‘𝑖), (𝑤‘(𝑖 + 1))} ∈ (Edg‘𝐺)) ∧ (♯‘𝑤) = (1 + 1))) |
8 | 3, 7 | bitri 274 |
. . . . . . 7
⊢ (𝑤 ∈ (1 WWalksN 𝐺) ↔ ((𝑤 ≠ ∅ ∧ 𝑤 ∈ Word 𝑉 ∧ ∀𝑖 ∈ (0..^((♯‘𝑤) − 1)){(𝑤‘𝑖), (𝑤‘(𝑖 + 1))} ∈ (Edg‘𝐺)) ∧ (♯‘𝑤) = (1 + 1))) |
9 | 8 | a1i 11 |
. . . . . 6
⊢ ((𝐺 RegUSGraph 𝐾 ∧ 𝑃 ∈ 𝑉) → (𝑤 ∈ (1 WWalksN 𝐺) ↔ ((𝑤 ≠ ∅ ∧ 𝑤 ∈ Word 𝑉 ∧ ∀𝑖 ∈ (0..^((♯‘𝑤) − 1)){(𝑤‘𝑖), (𝑤‘(𝑖 + 1))} ∈ (Edg‘𝐺)) ∧ (♯‘𝑤) = (1 + 1)))) |
10 | 9 | anbi1d 629 |
. . . . 5
⊢ ((𝐺 RegUSGraph 𝐾 ∧ 𝑃 ∈ 𝑉) → ((𝑤 ∈ (1 WWalksN 𝐺) ∧ (𝑤‘0) = 𝑃) ↔ (((𝑤 ≠ ∅ ∧ 𝑤 ∈ Word 𝑉 ∧ ∀𝑖 ∈ (0..^((♯‘𝑤) − 1)){(𝑤‘𝑖), (𝑤‘(𝑖 + 1))} ∈ (Edg‘𝐺)) ∧ (♯‘𝑤) = (1 + 1)) ∧ (𝑤‘0) = 𝑃))) |
11 | | 1p1e2 12028 |
. . . . . . . . . . 11
⊢ (1 + 1) =
2 |
12 | 11 | eqeq2i 2751 |
. . . . . . . . . 10
⊢
((♯‘𝑤) =
(1 + 1) ↔ (♯‘𝑤) = 2) |
13 | 12 | a1i 11 |
. . . . . . . . 9
⊢ ((𝐺 RegUSGraph 𝐾 ∧ 𝑃 ∈ 𝑉) → ((♯‘𝑤) = (1 + 1) ↔ (♯‘𝑤) = 2)) |
14 | 13 | anbi2d 628 |
. . . . . . . 8
⊢ ((𝐺 RegUSGraph 𝐾 ∧ 𝑃 ∈ 𝑉) → (((𝑤 ≠ ∅ ∧ 𝑤 ∈ Word 𝑉 ∧ ∀𝑖 ∈ (0..^((♯‘𝑤) − 1)){(𝑤‘𝑖), (𝑤‘(𝑖 + 1))} ∈ (Edg‘𝐺)) ∧ (♯‘𝑤) = (1 + 1)) ↔ ((𝑤 ≠ ∅ ∧ 𝑤 ∈ Word 𝑉 ∧ ∀𝑖 ∈ (0..^((♯‘𝑤) − 1)){(𝑤‘𝑖), (𝑤‘(𝑖 + 1))} ∈ (Edg‘𝐺)) ∧ (♯‘𝑤) = 2))) |
15 | | 3anass 1093 |
. . . . . . . . . . . 12
⊢ ((𝑤 ≠ ∅ ∧ 𝑤 ∈ Word 𝑉 ∧ ∀𝑖 ∈ (0..^((♯‘𝑤) − 1)){(𝑤‘𝑖), (𝑤‘(𝑖 + 1))} ∈ (Edg‘𝐺)) ↔ (𝑤 ≠ ∅ ∧ (𝑤 ∈ Word 𝑉 ∧ ∀𝑖 ∈ (0..^((♯‘𝑤) − 1)){(𝑤‘𝑖), (𝑤‘(𝑖 + 1))} ∈ (Edg‘𝐺)))) |
16 | 15 | a1i 11 |
. . . . . . . . . . 11
⊢ (((𝐺 RegUSGraph 𝐾 ∧ 𝑃 ∈ 𝑉) ∧ (♯‘𝑤) = 2) → ((𝑤 ≠ ∅ ∧ 𝑤 ∈ Word 𝑉 ∧ ∀𝑖 ∈ (0..^((♯‘𝑤) − 1)){(𝑤‘𝑖), (𝑤‘(𝑖 + 1))} ∈ (Edg‘𝐺)) ↔ (𝑤 ≠ ∅ ∧ (𝑤 ∈ Word 𝑉 ∧ ∀𝑖 ∈ (0..^((♯‘𝑤) − 1)){(𝑤‘𝑖), (𝑤‘(𝑖 + 1))} ∈ (Edg‘𝐺))))) |
17 | | fveq2 6756 |
. . . . . . . . . . . . . . . 16
⊢ (𝑤 = ∅ →
(♯‘𝑤) =
(♯‘∅)) |
18 | | hash0 14010 |
. . . . . . . . . . . . . . . 16
⊢
(♯‘∅) = 0 |
19 | 17, 18 | eqtrdi 2795 |
. . . . . . . . . . . . . . 15
⊢ (𝑤 = ∅ →
(♯‘𝑤) =
0) |
20 | | 2ne0 12007 |
. . . . . . . . . . . . . . . . 17
⊢ 2 ≠
0 |
21 | 20 | nesymi 3000 |
. . . . . . . . . . . . . . . 16
⊢ ¬ 0
= 2 |
22 | | eqeq1 2742 |
. . . . . . . . . . . . . . . 16
⊢
((♯‘𝑤) =
0 → ((♯‘𝑤)
= 2 ↔ 0 = 2)) |
23 | 21, 22 | mtbiri 326 |
. . . . . . . . . . . . . . 15
⊢
((♯‘𝑤) =
0 → ¬ (♯‘𝑤) = 2) |
24 | 19, 23 | syl 17 |
. . . . . . . . . . . . . 14
⊢ (𝑤 = ∅ → ¬
(♯‘𝑤) =
2) |
25 | 24 | necon2ai 2972 |
. . . . . . . . . . . . 13
⊢
((♯‘𝑤) =
2 → 𝑤 ≠
∅) |
26 | 25 | adantl 481 |
. . . . . . . . . . . 12
⊢ (((𝐺 RegUSGraph 𝐾 ∧ 𝑃 ∈ 𝑉) ∧ (♯‘𝑤) = 2) → 𝑤 ≠ ∅) |
27 | 26 | biantrurd 532 |
. . . . . . . . . . 11
⊢ (((𝐺 RegUSGraph 𝐾 ∧ 𝑃 ∈ 𝑉) ∧ (♯‘𝑤) = 2) → ((𝑤 ∈ Word 𝑉 ∧ ∀𝑖 ∈ (0..^((♯‘𝑤) − 1)){(𝑤‘𝑖), (𝑤‘(𝑖 + 1))} ∈ (Edg‘𝐺)) ↔ (𝑤 ≠ ∅ ∧ (𝑤 ∈ Word 𝑉 ∧ ∀𝑖 ∈ (0..^((♯‘𝑤) − 1)){(𝑤‘𝑖), (𝑤‘(𝑖 + 1))} ∈ (Edg‘𝐺))))) |
28 | | oveq1 7262 |
. . . . . . . . . . . . . . . . 17
⊢
((♯‘𝑤) =
2 → ((♯‘𝑤)
− 1) = (2 − 1)) |
29 | | 2m1e1 12029 |
. . . . . . . . . . . . . . . . 17
⊢ (2
− 1) = 1 |
30 | 28, 29 | eqtrdi 2795 |
. . . . . . . . . . . . . . . 16
⊢
((♯‘𝑤) =
2 → ((♯‘𝑤)
− 1) = 1) |
31 | 30 | oveq2d 7271 |
. . . . . . . . . . . . . . 15
⊢
((♯‘𝑤) =
2 → (0..^((♯‘𝑤) − 1)) = (0..^1)) |
32 | 31 | adantl 481 |
. . . . . . . . . . . . . 14
⊢ (((𝐺 RegUSGraph 𝐾 ∧ 𝑃 ∈ 𝑉) ∧ (♯‘𝑤) = 2) → (0..^((♯‘𝑤) − 1)) =
(0..^1)) |
33 | 32 | raleqdv 3339 |
. . . . . . . . . . . . 13
⊢ (((𝐺 RegUSGraph 𝐾 ∧ 𝑃 ∈ 𝑉) ∧ (♯‘𝑤) = 2) → (∀𝑖 ∈ (0..^((♯‘𝑤) − 1)){(𝑤‘𝑖), (𝑤‘(𝑖 + 1))} ∈ (Edg‘𝐺) ↔ ∀𝑖 ∈ (0..^1){(𝑤‘𝑖), (𝑤‘(𝑖 + 1))} ∈ (Edg‘𝐺))) |
34 | | fzo01 13397 |
. . . . . . . . . . . . . . 15
⊢ (0..^1) =
{0} |
35 | 34 | raleqi 3337 |
. . . . . . . . . . . . . 14
⊢
(∀𝑖 ∈
(0..^1){(𝑤‘𝑖), (𝑤‘(𝑖 + 1))} ∈ (Edg‘𝐺) ↔ ∀𝑖 ∈ {0} {(𝑤‘𝑖), (𝑤‘(𝑖 + 1))} ∈ (Edg‘𝐺)) |
36 | | c0ex 10900 |
. . . . . . . . . . . . . . 15
⊢ 0 ∈
V |
37 | | fveq2 6756 |
. . . . . . . . . . . . . . . . 17
⊢ (𝑖 = 0 → (𝑤‘𝑖) = (𝑤‘0)) |
38 | | fv0p1e1 12026 |
. . . . . . . . . . . . . . . . 17
⊢ (𝑖 = 0 → (𝑤‘(𝑖 + 1)) = (𝑤‘1)) |
39 | 37, 38 | preq12d 4674 |
. . . . . . . . . . . . . . . 16
⊢ (𝑖 = 0 → {(𝑤‘𝑖), (𝑤‘(𝑖 + 1))} = {(𝑤‘0), (𝑤‘1)}) |
40 | 39 | eleq1d 2823 |
. . . . . . . . . . . . . . 15
⊢ (𝑖 = 0 → ({(𝑤‘𝑖), (𝑤‘(𝑖 + 1))} ∈ (Edg‘𝐺) ↔ {(𝑤‘0), (𝑤‘1)} ∈ (Edg‘𝐺))) |
41 | 36, 40 | ralsn 4614 |
. . . . . . . . . . . . . 14
⊢
(∀𝑖 ∈
{0} {(𝑤‘𝑖), (𝑤‘(𝑖 + 1))} ∈ (Edg‘𝐺) ↔ {(𝑤‘0), (𝑤‘1)} ∈ (Edg‘𝐺)) |
42 | 35, 41 | bitri 274 |
. . . . . . . . . . . . 13
⊢
(∀𝑖 ∈
(0..^1){(𝑤‘𝑖), (𝑤‘(𝑖 + 1))} ∈ (Edg‘𝐺) ↔ {(𝑤‘0), (𝑤‘1)} ∈ (Edg‘𝐺)) |
43 | 33, 42 | bitrdi 286 |
. . . . . . . . . . . 12
⊢ (((𝐺 RegUSGraph 𝐾 ∧ 𝑃 ∈ 𝑉) ∧ (♯‘𝑤) = 2) → (∀𝑖 ∈ (0..^((♯‘𝑤) − 1)){(𝑤‘𝑖), (𝑤‘(𝑖 + 1))} ∈ (Edg‘𝐺) ↔ {(𝑤‘0), (𝑤‘1)} ∈ (Edg‘𝐺))) |
44 | 43 | anbi2d 628 |
. . . . . . . . . . 11
⊢ (((𝐺 RegUSGraph 𝐾 ∧ 𝑃 ∈ 𝑉) ∧ (♯‘𝑤) = 2) → ((𝑤 ∈ Word 𝑉 ∧ ∀𝑖 ∈ (0..^((♯‘𝑤) − 1)){(𝑤‘𝑖), (𝑤‘(𝑖 + 1))} ∈ (Edg‘𝐺)) ↔ (𝑤 ∈ Word 𝑉 ∧ {(𝑤‘0), (𝑤‘1)} ∈ (Edg‘𝐺)))) |
45 | 16, 27, 44 | 3bitr2d 306 |
. . . . . . . . . 10
⊢ (((𝐺 RegUSGraph 𝐾 ∧ 𝑃 ∈ 𝑉) ∧ (♯‘𝑤) = 2) → ((𝑤 ≠ ∅ ∧ 𝑤 ∈ Word 𝑉 ∧ ∀𝑖 ∈ (0..^((♯‘𝑤) − 1)){(𝑤‘𝑖), (𝑤‘(𝑖 + 1))} ∈ (Edg‘𝐺)) ↔ (𝑤 ∈ Word 𝑉 ∧ {(𝑤‘0), (𝑤‘1)} ∈ (Edg‘𝐺)))) |
46 | 45 | ex 412 |
. . . . . . . . 9
⊢ ((𝐺 RegUSGraph 𝐾 ∧ 𝑃 ∈ 𝑉) → ((♯‘𝑤) = 2 → ((𝑤 ≠ ∅ ∧ 𝑤 ∈ Word 𝑉 ∧ ∀𝑖 ∈ (0..^((♯‘𝑤) − 1)){(𝑤‘𝑖), (𝑤‘(𝑖 + 1))} ∈ (Edg‘𝐺)) ↔ (𝑤 ∈ Word 𝑉 ∧ {(𝑤‘0), (𝑤‘1)} ∈ (Edg‘𝐺))))) |
47 | 46 | pm5.32rd 577 |
. . . . . . . 8
⊢ ((𝐺 RegUSGraph 𝐾 ∧ 𝑃 ∈ 𝑉) → (((𝑤 ≠ ∅ ∧ 𝑤 ∈ Word 𝑉 ∧ ∀𝑖 ∈ (0..^((♯‘𝑤) − 1)){(𝑤‘𝑖), (𝑤‘(𝑖 + 1))} ∈ (Edg‘𝐺)) ∧ (♯‘𝑤) = 2) ↔ ((𝑤 ∈ Word 𝑉 ∧ {(𝑤‘0), (𝑤‘1)} ∈ (Edg‘𝐺)) ∧ (♯‘𝑤) = 2))) |
48 | 14, 47 | bitrd 278 |
. . . . . . 7
⊢ ((𝐺 RegUSGraph 𝐾 ∧ 𝑃 ∈ 𝑉) → (((𝑤 ≠ ∅ ∧ 𝑤 ∈ Word 𝑉 ∧ ∀𝑖 ∈ (0..^((♯‘𝑤) − 1)){(𝑤‘𝑖), (𝑤‘(𝑖 + 1))} ∈ (Edg‘𝐺)) ∧ (♯‘𝑤) = (1 + 1)) ↔ ((𝑤 ∈ Word 𝑉 ∧ {(𝑤‘0), (𝑤‘1)} ∈ (Edg‘𝐺)) ∧ (♯‘𝑤) = 2))) |
49 | 48 | anbi1d 629 |
. . . . . 6
⊢ ((𝐺 RegUSGraph 𝐾 ∧ 𝑃 ∈ 𝑉) → ((((𝑤 ≠ ∅ ∧ 𝑤 ∈ Word 𝑉 ∧ ∀𝑖 ∈ (0..^((♯‘𝑤) − 1)){(𝑤‘𝑖), (𝑤‘(𝑖 + 1))} ∈ (Edg‘𝐺)) ∧ (♯‘𝑤) = (1 + 1)) ∧ (𝑤‘0) = 𝑃) ↔ (((𝑤 ∈ Word 𝑉 ∧ {(𝑤‘0), (𝑤‘1)} ∈ (Edg‘𝐺)) ∧ (♯‘𝑤) = 2) ∧ (𝑤‘0) = 𝑃))) |
50 | | anass 468 |
. . . . . 6
⊢ ((((𝑤 ∈ Word 𝑉 ∧ {(𝑤‘0), (𝑤‘1)} ∈ (Edg‘𝐺)) ∧ (♯‘𝑤) = 2) ∧ (𝑤‘0) = 𝑃) ↔ ((𝑤 ∈ Word 𝑉 ∧ {(𝑤‘0), (𝑤‘1)} ∈ (Edg‘𝐺)) ∧ ((♯‘𝑤) = 2 ∧ (𝑤‘0) = 𝑃))) |
51 | 49, 50 | bitrdi 286 |
. . . . 5
⊢ ((𝐺 RegUSGraph 𝐾 ∧ 𝑃 ∈ 𝑉) → ((((𝑤 ≠ ∅ ∧ 𝑤 ∈ Word 𝑉 ∧ ∀𝑖 ∈ (0..^((♯‘𝑤) − 1)){(𝑤‘𝑖), (𝑤‘(𝑖 + 1))} ∈ (Edg‘𝐺)) ∧ (♯‘𝑤) = (1 + 1)) ∧ (𝑤‘0) = 𝑃) ↔ ((𝑤 ∈ Word 𝑉 ∧ {(𝑤‘0), (𝑤‘1)} ∈ (Edg‘𝐺)) ∧ ((♯‘𝑤) = 2 ∧ (𝑤‘0) = 𝑃)))) |
52 | | anass 468 |
. . . . . . 7
⊢ (((𝑤 ∈ Word 𝑉 ∧ {(𝑤‘0), (𝑤‘1)} ∈ (Edg‘𝐺)) ∧ ((♯‘𝑤) = 2 ∧ (𝑤‘0) = 𝑃)) ↔ (𝑤 ∈ Word 𝑉 ∧ ({(𝑤‘0), (𝑤‘1)} ∈ (Edg‘𝐺) ∧ ((♯‘𝑤) = 2 ∧ (𝑤‘0) = 𝑃)))) |
53 | | ancom 460 |
. . . . . . . . 9
⊢ (({(𝑤‘0), (𝑤‘1)} ∈ (Edg‘𝐺) ∧ ((♯‘𝑤) = 2 ∧ (𝑤‘0) = 𝑃)) ↔ (((♯‘𝑤) = 2 ∧ (𝑤‘0) = 𝑃) ∧ {(𝑤‘0), (𝑤‘1)} ∈ (Edg‘𝐺))) |
54 | | df-3an 1087 |
. . . . . . . . 9
⊢
(((♯‘𝑤)
= 2 ∧ (𝑤‘0) =
𝑃 ∧ {(𝑤‘0), (𝑤‘1)} ∈ (Edg‘𝐺)) ↔ (((♯‘𝑤) = 2 ∧ (𝑤‘0) = 𝑃) ∧ {(𝑤‘0), (𝑤‘1)} ∈ (Edg‘𝐺))) |
55 | 53, 54 | bitr4i 277 |
. . . . . . . 8
⊢ (({(𝑤‘0), (𝑤‘1)} ∈ (Edg‘𝐺) ∧ ((♯‘𝑤) = 2 ∧ (𝑤‘0) = 𝑃)) ↔ ((♯‘𝑤) = 2 ∧ (𝑤‘0) = 𝑃 ∧ {(𝑤‘0), (𝑤‘1)} ∈ (Edg‘𝐺))) |
56 | 55 | anbi2i 622 |
. . . . . . 7
⊢ ((𝑤 ∈ Word 𝑉 ∧ ({(𝑤‘0), (𝑤‘1)} ∈ (Edg‘𝐺) ∧ ((♯‘𝑤) = 2 ∧ (𝑤‘0) = 𝑃))) ↔ (𝑤 ∈ Word 𝑉 ∧ ((♯‘𝑤) = 2 ∧ (𝑤‘0) = 𝑃 ∧ {(𝑤‘0), (𝑤‘1)} ∈ (Edg‘𝐺)))) |
57 | 52, 56 | bitri 274 |
. . . . . 6
⊢ (((𝑤 ∈ Word 𝑉 ∧ {(𝑤‘0), (𝑤‘1)} ∈ (Edg‘𝐺)) ∧ ((♯‘𝑤) = 2 ∧ (𝑤‘0) = 𝑃)) ↔ (𝑤 ∈ Word 𝑉 ∧ ((♯‘𝑤) = 2 ∧ (𝑤‘0) = 𝑃 ∧ {(𝑤‘0), (𝑤‘1)} ∈ (Edg‘𝐺)))) |
58 | 57 | a1i 11 |
. . . . 5
⊢ ((𝐺 RegUSGraph 𝐾 ∧ 𝑃 ∈ 𝑉) → (((𝑤 ∈ Word 𝑉 ∧ {(𝑤‘0), (𝑤‘1)} ∈ (Edg‘𝐺)) ∧ ((♯‘𝑤) = 2 ∧ (𝑤‘0) = 𝑃)) ↔ (𝑤 ∈ Word 𝑉 ∧ ((♯‘𝑤) = 2 ∧ (𝑤‘0) = 𝑃 ∧ {(𝑤‘0), (𝑤‘1)} ∈ (Edg‘𝐺))))) |
59 | 10, 51, 58 | 3bitrd 304 |
. . . 4
⊢ ((𝐺 RegUSGraph 𝐾 ∧ 𝑃 ∈ 𝑉) → ((𝑤 ∈ (1 WWalksN 𝐺) ∧ (𝑤‘0) = 𝑃) ↔ (𝑤 ∈ Word 𝑉 ∧ ((♯‘𝑤) = 2 ∧ (𝑤‘0) = 𝑃 ∧ {(𝑤‘0), (𝑤‘1)} ∈ (Edg‘𝐺))))) |
60 | 59 | rabbidva2 3400 |
. . 3
⊢ ((𝐺 RegUSGraph 𝐾 ∧ 𝑃 ∈ 𝑉) → {𝑤 ∈ (1 WWalksN 𝐺) ∣ (𝑤‘0) = 𝑃} = {𝑤 ∈ Word 𝑉 ∣ ((♯‘𝑤) = 2 ∧ (𝑤‘0) = 𝑃 ∧ {(𝑤‘0), (𝑤‘1)} ∈ (Edg‘𝐺))}) |
61 | 60 | fveq2d 6760 |
. 2
⊢ ((𝐺 RegUSGraph 𝐾 ∧ 𝑃 ∈ 𝑉) → (♯‘{𝑤 ∈ (1 WWalksN 𝐺) ∣ (𝑤‘0) = 𝑃}) = (♯‘{𝑤 ∈ Word 𝑉 ∣ ((♯‘𝑤) = 2 ∧ (𝑤‘0) = 𝑃 ∧ {(𝑤‘0), (𝑤‘1)} ∈ (Edg‘𝐺))})) |
62 | 4 | rusgrnumwrdl2 27856 |
. 2
⊢ ((𝐺 RegUSGraph 𝐾 ∧ 𝑃 ∈ 𝑉) → (♯‘{𝑤 ∈ Word 𝑉 ∣ ((♯‘𝑤) = 2 ∧ (𝑤‘0) = 𝑃 ∧ {(𝑤‘0), (𝑤‘1)} ∈ (Edg‘𝐺))}) = 𝐾) |
63 | 61, 62 | eqtrd 2778 |
1
⊢ ((𝐺 RegUSGraph 𝐾 ∧ 𝑃 ∈ 𝑉) → (♯‘{𝑤 ∈ (1 WWalksN 𝐺) ∣ (𝑤‘0) = 𝑃}) = 𝐾) |