Proof of Theorem eupth2lem3lem7fi
| Step | Hyp | Ref
| Expression |
| 1 | | trlsegvdeg.v |
. . . . 5
⊢ 𝑉 = (Vtx‘𝐺) |
| 2 | | trlsegvdeg.i |
. . . . 5
⊢ 𝐼 = (iEdg‘𝐺) |
| 3 | | trlsegvdeg.f |
. . . . 5
⊢ (𝜑 → Fun 𝐼) |
| 4 | | trlsegvdeg.n |
. . . . 5
⊢ (𝜑 → 𝑁 ∈ (0..^(♯‘𝐹))) |
| 5 | | trlsegvdeg.u |
. . . . 5
⊢ (𝜑 → 𝑈 ∈ 𝑉) |
| 6 | | trlsegvdeg.w |
. . . . 5
⊢ (𝜑 → 𝐹(Trails‘𝐺)𝑃) |
| 7 | | trlsegvdeg.vx |
. . . . 5
⊢ (𝜑 → (Vtx‘𝑋) = 𝑉) |
| 8 | | trlsegvdeg.vy |
. . . . 5
⊢ (𝜑 → (Vtx‘𝑌) = 𝑉) |
| 9 | | trlsegvdeg.vz |
. . . . 5
⊢ (𝜑 → (Vtx‘𝑍) = 𝑉) |
| 10 | | trlsegvdeg.ix |
. . . . 5
⊢ (𝜑 → (iEdg‘𝑋) = (𝐼 ↾ (𝐹 “ (0..^𝑁)))) |
| 11 | | trlsegvdeg.iy |
. . . . 5
⊢ (𝜑 → (iEdg‘𝑌) = {〈(𝐹‘𝑁), (𝐼‘(𝐹‘𝑁))〉}) |
| 12 | | trlsegvdeg.iz |
. . . . 5
⊢ (𝜑 → (iEdg‘𝑍) = (𝐼 ↾ (𝐹 “ (0...𝑁)))) |
| 13 | | eupth2lem3lem7fi.g |
. . . . . 6
⊢ (𝜑 → 𝐺 ∈ UMGraph) |
| 14 | | umgrupgr 15966 |
. . . . . 6
⊢ (𝐺 ∈ UMGraph → 𝐺 ∈
UPGraph) |
| 15 | 13, 14 | syl 14 |
. . . . 5
⊢ (𝜑 → 𝐺 ∈ UPGraph) |
| 16 | | eupth2lem3lem7fi.v |
. . . . 5
⊢ (𝜑 → 𝑉 ∈ Fin) |
| 17 | 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,
11, 12, 15, 16 | trlsegvdegfi 16321 |
. . . 4
⊢ (𝜑 → ((VtxDeg‘𝑍)‘𝑈) = (((VtxDeg‘𝑋)‘𝑈) + ((VtxDeg‘𝑌)‘𝑈))) |
| 18 | 17 | breq2d 4100 |
. . 3
⊢ (𝜑 → (2 ∥
((VtxDeg‘𝑍)‘𝑈) ↔ 2 ∥ (((VtxDeg‘𝑋)‘𝑈) + ((VtxDeg‘𝑌)‘𝑈)))) |
| 19 | 18 | notbid 673 |
. 2
⊢ (𝜑 → (¬ 2 ∥
((VtxDeg‘𝑍)‘𝑈) ↔ ¬ 2 ∥
(((VtxDeg‘𝑋)‘𝑈) + ((VtxDeg‘𝑌)‘𝑈)))) |
| 20 | | eupth2lem3lem7fi.o |
. . . 4
⊢ (𝜑 → {𝑥 ∈ 𝑉 ∣ ¬ 2 ∥
((VtxDeg‘𝑋)‘𝑥)} = if((𝑃‘0) = (𝑃‘𝑁), ∅, {(𝑃‘0), (𝑃‘𝑁)})) |
| 21 | | eupth2lem3lem7fi.e |
. . . . 5
⊢ (𝜑 → (𝐼‘(𝐹‘𝑁)) = {(𝑃‘𝑁), (𝑃‘(𝑁 + 1))}) |
| 22 | | trliswlk 16240 |
. . . . . . . 8
⊢ (𝐹(Trails‘𝐺)𝑃 → 𝐹(Walks‘𝐺)𝑃) |
| 23 | 1 | wlkp 16188 |
. . . . . . . 8
⊢ (𝐹(Walks‘𝐺)𝑃 → 𝑃:(0...(♯‘𝐹))⟶𝑉) |
| 24 | 6, 22, 23 | 3syl 17 |
. . . . . . 7
⊢ (𝜑 → 𝑃:(0...(♯‘𝐹))⟶𝑉) |
| 25 | | elfzofz 10398 |
. . . . . . . 8
⊢ (𝑁 ∈
(0..^(♯‘𝐹))
→ 𝑁 ∈
(0...(♯‘𝐹))) |
| 26 | 4, 25 | syl 14 |
. . . . . . 7
⊢ (𝜑 → 𝑁 ∈ (0...(♯‘𝐹))) |
| 27 | 24, 26 | ffvelcdmd 5783 |
. . . . . 6
⊢ (𝜑 → (𝑃‘𝑁) ∈ 𝑉) |
| 28 | | fzofzp1 10473 |
. . . . . . . 8
⊢ (𝑁 ∈
(0..^(♯‘𝐹))
→ (𝑁 + 1) ∈
(0...(♯‘𝐹))) |
| 29 | 4, 28 | syl 14 |
. . . . . . 7
⊢ (𝜑 → (𝑁 + 1) ∈ (0...(♯‘𝐹))) |
| 30 | 24, 29 | ffvelcdmd 5783 |
. . . . . 6
⊢ (𝜑 → (𝑃‘(𝑁 + 1)) ∈ 𝑉) |
| 31 | | fidceq 7056 |
. . . . . 6
⊢ ((𝑉 ∈ Fin ∧ (𝑃‘𝑁) ∈ 𝑉 ∧ (𝑃‘(𝑁 + 1)) ∈ 𝑉) → DECID (𝑃‘𝑁) = (𝑃‘(𝑁 + 1))) |
| 32 | 16, 27, 30, 31 | syl3anc 1273 |
. . . . 5
⊢ (𝜑 → DECID
(𝑃‘𝑁) = (𝑃‘(𝑁 + 1))) |
| 33 | | ifpprsnssdc 3779 |
. . . . 5
⊢ (((𝐼‘(𝐹‘𝑁)) = {(𝑃‘𝑁), (𝑃‘(𝑁 + 1))} ∧ DECID (𝑃‘𝑁) = (𝑃‘(𝑁 + 1))) → if-((𝑃‘𝑁) = (𝑃‘(𝑁 + 1)), (𝐼‘(𝐹‘𝑁)) = {(𝑃‘𝑁)}, {(𝑃‘𝑁), (𝑃‘(𝑁 + 1))} ⊆ (𝐼‘(𝐹‘𝑁)))) |
| 34 | 21, 32, 33 | syl2anc 411 |
. . . 4
⊢ (𝜑 → if-((𝑃‘𝑁) = (𝑃‘(𝑁 + 1)), (𝐼‘(𝐹‘𝑁)) = {(𝑃‘𝑁)}, {(𝑃‘𝑁), (𝑃‘(𝑁 + 1))} ⊆ (𝐼‘(𝐹‘𝑁)))) |
| 35 | 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,
11, 12, 15, 16, 20, 34 | eupth2lem3lem3fi 16324 |
. . 3
⊢ ((𝜑 ∧ (𝑃‘𝑁) = (𝑃‘(𝑁 + 1))) → (¬ 2 ∥
(((VtxDeg‘𝑋)‘𝑈) + ((VtxDeg‘𝑌)‘𝑈)) ↔ 𝑈 ∈ if((𝑃‘0) = (𝑃‘(𝑁 + 1)), ∅, {(𝑃‘0), (𝑃‘(𝑁 + 1))}))) |
| 36 | 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,
11, 12, 20, 21 | eupth2lem3lem5 16326 |
. . . . . 6
⊢ (𝜑 → (𝐼‘(𝐹‘𝑁)) ∈ 𝒫 𝑉) |
| 37 | 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,
11, 12, 13, 16, 20, 34, 36 | eupth2lem3lem4fi 16327 |
. . . . 5
⊢ ((𝜑 ∧ (𝑃‘𝑁) ≠ (𝑃‘(𝑁 + 1)) ∧ (𝑈 = (𝑃‘𝑁) ∨ 𝑈 = (𝑃‘(𝑁 + 1)))) → (¬ 2 ∥
(((VtxDeg‘𝑋)‘𝑈) + ((VtxDeg‘𝑌)‘𝑈)) ↔ 𝑈 ∈ if((𝑃‘0) = (𝑃‘(𝑁 + 1)), ∅, {(𝑃‘0), (𝑃‘(𝑁 + 1))}))) |
| 38 | 37 | 3expa 1229 |
. . . 4
⊢ (((𝜑 ∧ (𝑃‘𝑁) ≠ (𝑃‘(𝑁 + 1))) ∧ (𝑈 = (𝑃‘𝑁) ∨ 𝑈 = (𝑃‘(𝑁 + 1)))) → (¬ 2 ∥
(((VtxDeg‘𝑋)‘𝑈) + ((VtxDeg‘𝑌)‘𝑈)) ↔ 𝑈 ∈ if((𝑃‘0) = (𝑃‘(𝑁 + 1)), ∅, {(𝑃‘0), (𝑃‘(𝑁 + 1))}))) |
| 39 | | neanior 2489 |
. . . . 5
⊢ ((𝑈 ≠ (𝑃‘𝑁) ∧ 𝑈 ≠ (𝑃‘(𝑁 + 1))) ↔ ¬ (𝑈 = (𝑃‘𝑁) ∨ 𝑈 = (𝑃‘(𝑁 + 1)))) |
| 40 | 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,
11, 12, 15, 16, 20, 21 | eupth2lem3lem6fi 16325 |
. . . . . 6
⊢ ((𝜑 ∧ (𝑃‘𝑁) ≠ (𝑃‘(𝑁 + 1)) ∧ (𝑈 ≠ (𝑃‘𝑁) ∧ 𝑈 ≠ (𝑃‘(𝑁 + 1)))) → (¬ 2 ∥
(((VtxDeg‘𝑋)‘𝑈) + ((VtxDeg‘𝑌)‘𝑈)) ↔ 𝑈 ∈ if((𝑃‘0) = (𝑃‘(𝑁 + 1)), ∅, {(𝑃‘0), (𝑃‘(𝑁 + 1))}))) |
| 41 | 40 | 3expa 1229 |
. . . . 5
⊢ (((𝜑 ∧ (𝑃‘𝑁) ≠ (𝑃‘(𝑁 + 1))) ∧ (𝑈 ≠ (𝑃‘𝑁) ∧ 𝑈 ≠ (𝑃‘(𝑁 + 1)))) → (¬ 2 ∥
(((VtxDeg‘𝑋)‘𝑈) + ((VtxDeg‘𝑌)‘𝑈)) ↔ 𝑈 ∈ if((𝑃‘0) = (𝑃‘(𝑁 + 1)), ∅, {(𝑃‘0), (𝑃‘(𝑁 + 1))}))) |
| 42 | 39, 41 | sylan2br 288 |
. . . 4
⊢ (((𝜑 ∧ (𝑃‘𝑁) ≠ (𝑃‘(𝑁 + 1))) ∧ ¬ (𝑈 = (𝑃‘𝑁) ∨ 𝑈 = (𝑃‘(𝑁 + 1)))) → (¬ 2 ∥
(((VtxDeg‘𝑋)‘𝑈) + ((VtxDeg‘𝑌)‘𝑈)) ↔ 𝑈 ∈ if((𝑃‘0) = (𝑃‘(𝑁 + 1)), ∅, {(𝑃‘0), (𝑃‘(𝑁 + 1))}))) |
| 43 | | fidceq 7056 |
. . . . . . . 8
⊢ ((𝑉 ∈ Fin ∧ 𝑈 ∈ 𝑉 ∧ (𝑃‘𝑁) ∈ 𝑉) → DECID 𝑈 = (𝑃‘𝑁)) |
| 44 | 16, 5, 27, 43 | syl3anc 1273 |
. . . . . . 7
⊢ (𝜑 → DECID 𝑈 = (𝑃‘𝑁)) |
| 45 | 44 | adantr 276 |
. . . . . 6
⊢ ((𝜑 ∧ (𝑃‘𝑁) ≠ (𝑃‘(𝑁 + 1))) → DECID 𝑈 = (𝑃‘𝑁)) |
| 46 | | fidceq 7056 |
. . . . . . . 8
⊢ ((𝑉 ∈ Fin ∧ 𝑈 ∈ 𝑉 ∧ (𝑃‘(𝑁 + 1)) ∈ 𝑉) → DECID 𝑈 = (𝑃‘(𝑁 + 1))) |
| 47 | 16, 5, 30, 46 | syl3anc 1273 |
. . . . . . 7
⊢ (𝜑 → DECID 𝑈 = (𝑃‘(𝑁 + 1))) |
| 48 | 47 | adantr 276 |
. . . . . 6
⊢ ((𝜑 ∧ (𝑃‘𝑁) ≠ (𝑃‘(𝑁 + 1))) → DECID 𝑈 = (𝑃‘(𝑁 + 1))) |
| 49 | | dcor 943 |
. . . . . 6
⊢
(DECID 𝑈 = (𝑃‘𝑁) → (DECID 𝑈 = (𝑃‘(𝑁 + 1)) → DECID (𝑈 = (𝑃‘𝑁) ∨ 𝑈 = (𝑃‘(𝑁 + 1))))) |
| 50 | 45, 48, 49 | sylc 62 |
. . . . 5
⊢ ((𝜑 ∧ (𝑃‘𝑁) ≠ (𝑃‘(𝑁 + 1))) → DECID (𝑈 = (𝑃‘𝑁) ∨ 𝑈 = (𝑃‘(𝑁 + 1)))) |
| 51 | | exmiddc 843 |
. . . . 5
⊢
(DECID (𝑈 = (𝑃‘𝑁) ∨ 𝑈 = (𝑃‘(𝑁 + 1))) → ((𝑈 = (𝑃‘𝑁) ∨ 𝑈 = (𝑃‘(𝑁 + 1))) ∨ ¬ (𝑈 = (𝑃‘𝑁) ∨ 𝑈 = (𝑃‘(𝑁 + 1))))) |
| 52 | 50, 51 | syl 14 |
. . . 4
⊢ ((𝜑 ∧ (𝑃‘𝑁) ≠ (𝑃‘(𝑁 + 1))) → ((𝑈 = (𝑃‘𝑁) ∨ 𝑈 = (𝑃‘(𝑁 + 1))) ∨ ¬ (𝑈 = (𝑃‘𝑁) ∨ 𝑈 = (𝑃‘(𝑁 + 1))))) |
| 53 | 38, 42, 52 | mpjaodan 805 |
. . 3
⊢ ((𝜑 ∧ (𝑃‘𝑁) ≠ (𝑃‘(𝑁 + 1))) → (¬ 2 ∥
(((VtxDeg‘𝑋)‘𝑈) + ((VtxDeg‘𝑌)‘𝑈)) ↔ 𝑈 ∈ if((𝑃‘0) = (𝑃‘(𝑁 + 1)), ∅, {(𝑃‘0), (𝑃‘(𝑁 + 1))}))) |
| 54 | | dcne 2413 |
. . . 4
⊢
(DECID (𝑃‘𝑁) = (𝑃‘(𝑁 + 1)) ↔ ((𝑃‘𝑁) = (𝑃‘(𝑁 + 1)) ∨ (𝑃‘𝑁) ≠ (𝑃‘(𝑁 + 1)))) |
| 55 | 32, 54 | sylib 122 |
. . 3
⊢ (𝜑 → ((𝑃‘𝑁) = (𝑃‘(𝑁 + 1)) ∨ (𝑃‘𝑁) ≠ (𝑃‘(𝑁 + 1)))) |
| 56 | 35, 53, 55 | mpjaodan 805 |
. 2
⊢ (𝜑 → (¬ 2 ∥
(((VtxDeg‘𝑋)‘𝑈) + ((VtxDeg‘𝑌)‘𝑈)) ↔ 𝑈 ∈ if((𝑃‘0) = (𝑃‘(𝑁 + 1)), ∅, {(𝑃‘0), (𝑃‘(𝑁 + 1))}))) |
| 57 | 19, 56 | bitrd 188 |
1
⊢ (𝜑 → (¬ 2 ∥
((VtxDeg‘𝑍)‘𝑈) ↔ 𝑈 ∈ if((𝑃‘0) = (𝑃‘(𝑁 + 1)), ∅, {(𝑃‘0), (𝑃‘(𝑁 + 1))}))) |