Step | Hyp | Ref
| Expression |
1 | | frgrusgr 28526 |
. . . . . 6
⊢ (𝐺 ∈ FriendGraph → 𝐺 ∈
USGraph) |
2 | 1 | anim1i 614 |
. . . . 5
⊢ ((𝐺 ∈ FriendGraph ∧ 𝑁 ∈ 𝑉) → (𝐺 ∈ USGraph ∧ 𝑁 ∈ 𝑉)) |
3 | 2 | adantr 480 |
. . . 4
⊢ (((𝐺 ∈ FriendGraph ∧ 𝑁 ∈ 𝑉) ∧ 1 < (♯‘𝑉)) → (𝐺 ∈ USGraph ∧ 𝑁 ∈ 𝑉)) |
4 | | vdn1frgrv2.v |
. . . . 5
⊢ 𝑉 = (Vtx‘𝐺) |
5 | | eqid 2738 |
. . . . 5
⊢
(iEdg‘𝐺) =
(iEdg‘𝐺) |
6 | | eqid 2738 |
. . . . 5
⊢ dom
(iEdg‘𝐺) = dom
(iEdg‘𝐺) |
7 | | eqid 2738 |
. . . . 5
⊢
(VtxDeg‘𝐺) =
(VtxDeg‘𝐺) |
8 | 4, 5, 6, 7 | vtxdusgrval 27757 |
. . . 4
⊢ ((𝐺 ∈ USGraph ∧ 𝑁 ∈ 𝑉) → ((VtxDeg‘𝐺)‘𝑁) = (♯‘{𝑥 ∈ dom (iEdg‘𝐺) ∣ 𝑁 ∈ ((iEdg‘𝐺)‘𝑥)})) |
9 | 3, 8 | syl 17 |
. . 3
⊢ (((𝐺 ∈ FriendGraph ∧ 𝑁 ∈ 𝑉) ∧ 1 < (♯‘𝑉)) → ((VtxDeg‘𝐺)‘𝑁) = (♯‘{𝑥 ∈ dom (iEdg‘𝐺) ∣ 𝑁 ∈ ((iEdg‘𝐺)‘𝑥)})) |
10 | | eqid 2738 |
. . . . . . 7
⊢
(Edg‘𝐺) =
(Edg‘𝐺) |
11 | 4, 10 | 3cyclfrgrrn2 28552 |
. . . . . 6
⊢ ((𝐺 ∈ FriendGraph ∧ 1 <
(♯‘𝑉)) →
∀𝑎 ∈ 𝑉 ∃𝑏 ∈ 𝑉 ∃𝑐 ∈ 𝑉 (𝑏 ≠ 𝑐 ∧ ({𝑎, 𝑏} ∈ (Edg‘𝐺) ∧ {𝑏, 𝑐} ∈ (Edg‘𝐺) ∧ {𝑐, 𝑎} ∈ (Edg‘𝐺)))) |
12 | 11 | adantlr 711 |
. . . . 5
⊢ (((𝐺 ∈ FriendGraph ∧ 𝑁 ∈ 𝑉) ∧ 1 < (♯‘𝑉)) → ∀𝑎 ∈ 𝑉 ∃𝑏 ∈ 𝑉 ∃𝑐 ∈ 𝑉 (𝑏 ≠ 𝑐 ∧ ({𝑎, 𝑏} ∈ (Edg‘𝐺) ∧ {𝑏, 𝑐} ∈ (Edg‘𝐺) ∧ {𝑐, 𝑎} ∈ (Edg‘𝐺)))) |
13 | | preq1 4666 |
. . . . . . . . . . . . . . . 16
⊢ (𝑎 = 𝑁 → {𝑎, 𝑏} = {𝑁, 𝑏}) |
14 | 13 | eleq1d 2823 |
. . . . . . . . . . . . . . 15
⊢ (𝑎 = 𝑁 → ({𝑎, 𝑏} ∈ (Edg‘𝐺) ↔ {𝑁, 𝑏} ∈ (Edg‘𝐺))) |
15 | | preq2 4667 |
. . . . . . . . . . . . . . . 16
⊢ (𝑎 = 𝑁 → {𝑐, 𝑎} = {𝑐, 𝑁}) |
16 | 15 | eleq1d 2823 |
. . . . . . . . . . . . . . 15
⊢ (𝑎 = 𝑁 → ({𝑐, 𝑎} ∈ (Edg‘𝐺) ↔ {𝑐, 𝑁} ∈ (Edg‘𝐺))) |
17 | 14, 16 | 3anbi13d 1436 |
. . . . . . . . . . . . . 14
⊢ (𝑎 = 𝑁 → (({𝑎, 𝑏} ∈ (Edg‘𝐺) ∧ {𝑏, 𝑐} ∈ (Edg‘𝐺) ∧ {𝑐, 𝑎} ∈ (Edg‘𝐺)) ↔ ({𝑁, 𝑏} ∈ (Edg‘𝐺) ∧ {𝑏, 𝑐} ∈ (Edg‘𝐺) ∧ {𝑐, 𝑁} ∈ (Edg‘𝐺)))) |
18 | 17 | anbi2d 628 |
. . . . . . . . . . . . 13
⊢ (𝑎 = 𝑁 → ((𝑏 ≠ 𝑐 ∧ ({𝑎, 𝑏} ∈ (Edg‘𝐺) ∧ {𝑏, 𝑐} ∈ (Edg‘𝐺) ∧ {𝑐, 𝑎} ∈ (Edg‘𝐺))) ↔ (𝑏 ≠ 𝑐 ∧ ({𝑁, 𝑏} ∈ (Edg‘𝐺) ∧ {𝑏, 𝑐} ∈ (Edg‘𝐺) ∧ {𝑐, 𝑁} ∈ (Edg‘𝐺))))) |
19 | 18 | 2rexbidv 3228 |
. . . . . . . . . . . 12
⊢ (𝑎 = 𝑁 → (∃𝑏 ∈ 𝑉 ∃𝑐 ∈ 𝑉 (𝑏 ≠ 𝑐 ∧ ({𝑎, 𝑏} ∈ (Edg‘𝐺) ∧ {𝑏, 𝑐} ∈ (Edg‘𝐺) ∧ {𝑐, 𝑎} ∈ (Edg‘𝐺))) ↔ ∃𝑏 ∈ 𝑉 ∃𝑐 ∈ 𝑉 (𝑏 ≠ 𝑐 ∧ ({𝑁, 𝑏} ∈ (Edg‘𝐺) ∧ {𝑏, 𝑐} ∈ (Edg‘𝐺) ∧ {𝑐, 𝑁} ∈ (Edg‘𝐺))))) |
20 | 19 | rspcva 3550 |
. . . . . . . . . . 11
⊢ ((𝑁 ∈ 𝑉 ∧ ∀𝑎 ∈ 𝑉 ∃𝑏 ∈ 𝑉 ∃𝑐 ∈ 𝑉 (𝑏 ≠ 𝑐 ∧ ({𝑎, 𝑏} ∈ (Edg‘𝐺) ∧ {𝑏, 𝑐} ∈ (Edg‘𝐺) ∧ {𝑐, 𝑎} ∈ (Edg‘𝐺)))) → ∃𝑏 ∈ 𝑉 ∃𝑐 ∈ 𝑉 (𝑏 ≠ 𝑐 ∧ ({𝑁, 𝑏} ∈ (Edg‘𝐺) ∧ {𝑏, 𝑐} ∈ (Edg‘𝐺) ∧ {𝑐, 𝑁} ∈ (Edg‘𝐺)))) |
21 | 1 | adantl 481 |
. . . . . . . . . . . . . . . . 17
⊢ ((((𝑏 ≠ 𝑐 ∧ ({𝑁, 𝑏} ∈ (Edg‘𝐺) ∧ {𝑏, 𝑐} ∈ (Edg‘𝐺) ∧ {𝑐, 𝑁} ∈ (Edg‘𝐺))) ∧ 𝑁 ∈ 𝑉) ∧ 𝐺 ∈ FriendGraph ) → 𝐺 ∈
USGraph) |
22 | | simplll 771 |
. . . . . . . . . . . . . . . . 17
⊢ ((((𝑏 ≠ 𝑐 ∧ ({𝑁, 𝑏} ∈ (Edg‘𝐺) ∧ {𝑏, 𝑐} ∈ (Edg‘𝐺) ∧ {𝑐, 𝑁} ∈ (Edg‘𝐺))) ∧ 𝑁 ∈ 𝑉) ∧ 𝐺 ∈ FriendGraph ) → 𝑏 ≠ 𝑐) |
23 | | 3simpb 1147 |
. . . . . . . . . . . . . . . . . 18
⊢ (({𝑁, 𝑏} ∈ (Edg‘𝐺) ∧ {𝑏, 𝑐} ∈ (Edg‘𝐺) ∧ {𝑐, 𝑁} ∈ (Edg‘𝐺)) → ({𝑁, 𝑏} ∈ (Edg‘𝐺) ∧ {𝑐, 𝑁} ∈ (Edg‘𝐺))) |
24 | 23 | ad3antlr 727 |
. . . . . . . . . . . . . . . . 17
⊢ ((((𝑏 ≠ 𝑐 ∧ ({𝑁, 𝑏} ∈ (Edg‘𝐺) ∧ {𝑏, 𝑐} ∈ (Edg‘𝐺) ∧ {𝑐, 𝑁} ∈ (Edg‘𝐺))) ∧ 𝑁 ∈ 𝑉) ∧ 𝐺 ∈ FriendGraph ) → ({𝑁, 𝑏} ∈ (Edg‘𝐺) ∧ {𝑐, 𝑁} ∈ (Edg‘𝐺))) |
25 | 5, 10 | usgr2edg1 27482 |
. . . . . . . . . . . . . . . . 17
⊢ (((𝐺 ∈ USGraph ∧ 𝑏 ≠ 𝑐) ∧ ({𝑁, 𝑏} ∈ (Edg‘𝐺) ∧ {𝑐, 𝑁} ∈ (Edg‘𝐺))) → ¬ ∃!𝑥 ∈ dom (iEdg‘𝐺)𝑁 ∈ ((iEdg‘𝐺)‘𝑥)) |
26 | 21, 22, 24, 25 | syl21anc 834 |
. . . . . . . . . . . . . . . 16
⊢ ((((𝑏 ≠ 𝑐 ∧ ({𝑁, 𝑏} ∈ (Edg‘𝐺) ∧ {𝑏, 𝑐} ∈ (Edg‘𝐺) ∧ {𝑐, 𝑁} ∈ (Edg‘𝐺))) ∧ 𝑁 ∈ 𝑉) ∧ 𝐺 ∈ FriendGraph ) → ¬
∃!𝑥 ∈ dom
(iEdg‘𝐺)𝑁 ∈ ((iEdg‘𝐺)‘𝑥)) |
27 | 26 | a1d 25 |
. . . . . . . . . . . . . . 15
⊢ ((((𝑏 ≠ 𝑐 ∧ ({𝑁, 𝑏} ∈ (Edg‘𝐺) ∧ {𝑏, 𝑐} ∈ (Edg‘𝐺) ∧ {𝑐, 𝑁} ∈ (Edg‘𝐺))) ∧ 𝑁 ∈ 𝑉) ∧ 𝐺 ∈ FriendGraph ) → (1 <
(♯‘𝑉) →
¬ ∃!𝑥 ∈ dom
(iEdg‘𝐺)𝑁 ∈ ((iEdg‘𝐺)‘𝑥))) |
28 | 27 | ex 412 |
. . . . . . . . . . . . . 14
⊢ (((𝑏 ≠ 𝑐 ∧ ({𝑁, 𝑏} ∈ (Edg‘𝐺) ∧ {𝑏, 𝑐} ∈ (Edg‘𝐺) ∧ {𝑐, 𝑁} ∈ (Edg‘𝐺))) ∧ 𝑁 ∈ 𝑉) → (𝐺 ∈ FriendGraph → (1 <
(♯‘𝑉) →
¬ ∃!𝑥 ∈ dom
(iEdg‘𝐺)𝑁 ∈ ((iEdg‘𝐺)‘𝑥)))) |
29 | 28 | ex 412 |
. . . . . . . . . . . . 13
⊢ ((𝑏 ≠ 𝑐 ∧ ({𝑁, 𝑏} ∈ (Edg‘𝐺) ∧ {𝑏, 𝑐} ∈ (Edg‘𝐺) ∧ {𝑐, 𝑁} ∈ (Edg‘𝐺))) → (𝑁 ∈ 𝑉 → (𝐺 ∈ FriendGraph → (1 <
(♯‘𝑉) →
¬ ∃!𝑥 ∈ dom
(iEdg‘𝐺)𝑁 ∈ ((iEdg‘𝐺)‘𝑥))))) |
30 | 29 | a1i 11 |
. . . . . . . . . . . 12
⊢ ((𝑏 ∈ 𝑉 ∧ 𝑐 ∈ 𝑉) → ((𝑏 ≠ 𝑐 ∧ ({𝑁, 𝑏} ∈ (Edg‘𝐺) ∧ {𝑏, 𝑐} ∈ (Edg‘𝐺) ∧ {𝑐, 𝑁} ∈ (Edg‘𝐺))) → (𝑁 ∈ 𝑉 → (𝐺 ∈ FriendGraph → (1 <
(♯‘𝑉) →
¬ ∃!𝑥 ∈ dom
(iEdg‘𝐺)𝑁 ∈ ((iEdg‘𝐺)‘𝑥)))))) |
31 | 30 | rexlimivv 3220 |
. . . . . . . . . . 11
⊢
(∃𝑏 ∈
𝑉 ∃𝑐 ∈ 𝑉 (𝑏 ≠ 𝑐 ∧ ({𝑁, 𝑏} ∈ (Edg‘𝐺) ∧ {𝑏, 𝑐} ∈ (Edg‘𝐺) ∧ {𝑐, 𝑁} ∈ (Edg‘𝐺))) → (𝑁 ∈ 𝑉 → (𝐺 ∈ FriendGraph → (1 <
(♯‘𝑉) →
¬ ∃!𝑥 ∈ dom
(iEdg‘𝐺)𝑁 ∈ ((iEdg‘𝐺)‘𝑥))))) |
32 | 20, 31 | syl 17 |
. . . . . . . . . 10
⊢ ((𝑁 ∈ 𝑉 ∧ ∀𝑎 ∈ 𝑉 ∃𝑏 ∈ 𝑉 ∃𝑐 ∈ 𝑉 (𝑏 ≠ 𝑐 ∧ ({𝑎, 𝑏} ∈ (Edg‘𝐺) ∧ {𝑏, 𝑐} ∈ (Edg‘𝐺) ∧ {𝑐, 𝑎} ∈ (Edg‘𝐺)))) → (𝑁 ∈ 𝑉 → (𝐺 ∈ FriendGraph → (1 <
(♯‘𝑉) →
¬ ∃!𝑥 ∈ dom
(iEdg‘𝐺)𝑁 ∈ ((iEdg‘𝐺)‘𝑥))))) |
33 | 32 | ex 412 |
. . . . . . . . 9
⊢ (𝑁 ∈ 𝑉 → (∀𝑎 ∈ 𝑉 ∃𝑏 ∈ 𝑉 ∃𝑐 ∈ 𝑉 (𝑏 ≠ 𝑐 ∧ ({𝑎, 𝑏} ∈ (Edg‘𝐺) ∧ {𝑏, 𝑐} ∈ (Edg‘𝐺) ∧ {𝑐, 𝑎} ∈ (Edg‘𝐺))) → (𝑁 ∈ 𝑉 → (𝐺 ∈ FriendGraph → (1 <
(♯‘𝑉) →
¬ ∃!𝑥 ∈ dom
(iEdg‘𝐺)𝑁 ∈ ((iEdg‘𝐺)‘𝑥)))))) |
34 | 33 | pm2.43a 54 |
. . . . . . . 8
⊢ (𝑁 ∈ 𝑉 → (∀𝑎 ∈ 𝑉 ∃𝑏 ∈ 𝑉 ∃𝑐 ∈ 𝑉 (𝑏 ≠ 𝑐 ∧ ({𝑎, 𝑏} ∈ (Edg‘𝐺) ∧ {𝑏, 𝑐} ∈ (Edg‘𝐺) ∧ {𝑐, 𝑎} ∈ (Edg‘𝐺))) → (𝐺 ∈ FriendGraph → (1 <
(♯‘𝑉) →
¬ ∃!𝑥 ∈ dom
(iEdg‘𝐺)𝑁 ∈ ((iEdg‘𝐺)‘𝑥))))) |
35 | 34 | com24 95 |
. . . . . . 7
⊢ (𝑁 ∈ 𝑉 → (1 < (♯‘𝑉) → (𝐺 ∈ FriendGraph → (∀𝑎 ∈ 𝑉 ∃𝑏 ∈ 𝑉 ∃𝑐 ∈ 𝑉 (𝑏 ≠ 𝑐 ∧ ({𝑎, 𝑏} ∈ (Edg‘𝐺) ∧ {𝑏, 𝑐} ∈ (Edg‘𝐺) ∧ {𝑐, 𝑎} ∈ (Edg‘𝐺))) → ¬ ∃!𝑥 ∈ dom (iEdg‘𝐺)𝑁 ∈ ((iEdg‘𝐺)‘𝑥))))) |
36 | 35 | com3r 87 |
. . . . . 6
⊢ (𝐺 ∈ FriendGraph →
(𝑁 ∈ 𝑉 → (1 < (♯‘𝑉) → (∀𝑎 ∈ 𝑉 ∃𝑏 ∈ 𝑉 ∃𝑐 ∈ 𝑉 (𝑏 ≠ 𝑐 ∧ ({𝑎, 𝑏} ∈ (Edg‘𝐺) ∧ {𝑏, 𝑐} ∈ (Edg‘𝐺) ∧ {𝑐, 𝑎} ∈ (Edg‘𝐺))) → ¬ ∃!𝑥 ∈ dom (iEdg‘𝐺)𝑁 ∈ ((iEdg‘𝐺)‘𝑥))))) |
37 | 36 | imp31 417 |
. . . . 5
⊢ (((𝐺 ∈ FriendGraph ∧ 𝑁 ∈ 𝑉) ∧ 1 < (♯‘𝑉)) → (∀𝑎 ∈ 𝑉 ∃𝑏 ∈ 𝑉 ∃𝑐 ∈ 𝑉 (𝑏 ≠ 𝑐 ∧ ({𝑎, 𝑏} ∈ (Edg‘𝐺) ∧ {𝑏, 𝑐} ∈ (Edg‘𝐺) ∧ {𝑐, 𝑎} ∈ (Edg‘𝐺))) → ¬ ∃!𝑥 ∈ dom (iEdg‘𝐺)𝑁 ∈ ((iEdg‘𝐺)‘𝑥))) |
38 | 12, 37 | mpd 15 |
. . . 4
⊢ (((𝐺 ∈ FriendGraph ∧ 𝑁 ∈ 𝑉) ∧ 1 < (♯‘𝑉)) → ¬ ∃!𝑥 ∈ dom (iEdg‘𝐺)𝑁 ∈ ((iEdg‘𝐺)‘𝑥)) |
39 | | fvex 6769 |
. . . . . . . . 9
⊢
(iEdg‘𝐺)
∈ V |
40 | 39 | dmex 7732 |
. . . . . . . 8
⊢ dom
(iEdg‘𝐺) ∈
V |
41 | 40 | a1i 11 |
. . . . . . 7
⊢ (((𝐺 ∈ FriendGraph ∧ 𝑁 ∈ 𝑉) ∧ 1 < (♯‘𝑉)) → dom (iEdg‘𝐺) ∈ V) |
42 | | rabexg 5250 |
. . . . . . 7
⊢ (dom
(iEdg‘𝐺) ∈ V
→ {𝑥 ∈ dom
(iEdg‘𝐺) ∣
𝑁 ∈ ((iEdg‘𝐺)‘𝑥)} ∈ V) |
43 | | hash1snb 14062 |
. . . . . . 7
⊢ ({𝑥 ∈ dom (iEdg‘𝐺) ∣ 𝑁 ∈ ((iEdg‘𝐺)‘𝑥)} ∈ V → ((♯‘{𝑥 ∈ dom (iEdg‘𝐺) ∣ 𝑁 ∈ ((iEdg‘𝐺)‘𝑥)}) = 1 ↔ ∃𝑖{𝑥 ∈ dom (iEdg‘𝐺) ∣ 𝑁 ∈ ((iEdg‘𝐺)‘𝑥)} = {𝑖})) |
44 | 41, 42, 43 | 3syl 18 |
. . . . . 6
⊢ (((𝐺 ∈ FriendGraph ∧ 𝑁 ∈ 𝑉) ∧ 1 < (♯‘𝑉)) → ((♯‘{𝑥 ∈ dom (iEdg‘𝐺) ∣ 𝑁 ∈ ((iEdg‘𝐺)‘𝑥)}) = 1 ↔ ∃𝑖{𝑥 ∈ dom (iEdg‘𝐺) ∣ 𝑁 ∈ ((iEdg‘𝐺)‘𝑥)} = {𝑖})) |
45 | | reusn 4660 |
. . . . . 6
⊢
(∃!𝑥 ∈
dom (iEdg‘𝐺)𝑁 ∈ ((iEdg‘𝐺)‘𝑥) ↔ ∃𝑖{𝑥 ∈ dom (iEdg‘𝐺) ∣ 𝑁 ∈ ((iEdg‘𝐺)‘𝑥)} = {𝑖}) |
46 | 44, 45 | bitr4di 288 |
. . . . 5
⊢ (((𝐺 ∈ FriendGraph ∧ 𝑁 ∈ 𝑉) ∧ 1 < (♯‘𝑉)) → ((♯‘{𝑥 ∈ dom (iEdg‘𝐺) ∣ 𝑁 ∈ ((iEdg‘𝐺)‘𝑥)}) = 1 ↔ ∃!𝑥 ∈ dom (iEdg‘𝐺)𝑁 ∈ ((iEdg‘𝐺)‘𝑥))) |
47 | 46 | necon3abid 2979 |
. . . 4
⊢ (((𝐺 ∈ FriendGraph ∧ 𝑁 ∈ 𝑉) ∧ 1 < (♯‘𝑉)) → ((♯‘{𝑥 ∈ dom (iEdg‘𝐺) ∣ 𝑁 ∈ ((iEdg‘𝐺)‘𝑥)}) ≠ 1 ↔ ¬ ∃!𝑥 ∈ dom (iEdg‘𝐺)𝑁 ∈ ((iEdg‘𝐺)‘𝑥))) |
48 | 38, 47 | mpbird 256 |
. . 3
⊢ (((𝐺 ∈ FriendGraph ∧ 𝑁 ∈ 𝑉) ∧ 1 < (♯‘𝑉)) → (♯‘{𝑥 ∈ dom (iEdg‘𝐺) ∣ 𝑁 ∈ ((iEdg‘𝐺)‘𝑥)}) ≠ 1) |
49 | 9, 48 | eqnetrd 3010 |
. 2
⊢ (((𝐺 ∈ FriendGraph ∧ 𝑁 ∈ 𝑉) ∧ 1 < (♯‘𝑉)) → ((VtxDeg‘𝐺)‘𝑁) ≠ 1) |
50 | 49 | ex 412 |
1
⊢ ((𝐺 ∈ FriendGraph ∧ 𝑁 ∈ 𝑉) → (1 < (♯‘𝑉) → ((VtxDeg‘𝐺)‘𝑁) ≠ 1)) |