Step | Hyp | Ref
| Expression |
1 | | eqid 2731 |
. . . 4
β’
(VtxβπΊ) =
(VtxβπΊ) |
2 | | eqid 2731 |
. . . 4
β’
(iEdgβπΊ) =
(iEdgβπΊ) |
3 | 1, 2 | umgrf 28622 |
. . 3
β’ (πΊ β UMGraph β
(iEdgβπΊ):dom
(iEdgβπΊ)βΆ{π₯ β π« (VtxβπΊ) β£ (β―βπ₯) = 2}) |
4 | | isacycgr 34431 |
. . . . 5
β’ (πΊ β UMGraph β (πΊ β AcyclicGraph β
Β¬ βπβπ(π(CyclesβπΊ)π β§ π β β
))) |
5 | 4 | biimpa 476 |
. . . 4
β’ ((πΊ β UMGraph β§ πΊ β AcyclicGraph) β
Β¬ βπβπ(π(CyclesβπΊ)π β§ π β β
)) |
6 | 2 | umgr2cycl 34427 |
. . . . . . . 8
β’ ((πΊ β UMGraph β§
βπ β dom
(iEdgβπΊ)βπ β dom (iEdgβπΊ)(((iEdgβπΊ)βπ) = ((iEdgβπΊ)βπ) β§ π β π)) β βπβπ(π(CyclesβπΊ)π β§ (β―βπ) = 2)) |
7 | | 2ne0 12321 |
. . . . . . . . . . . 12
β’ 2 β
0 |
8 | | neeq1 3002 |
. . . . . . . . . . . 12
β’
((β―βπ) =
2 β ((β―βπ)
β 0 β 2 β 0)) |
9 | 7, 8 | mpbiri 257 |
. . . . . . . . . . 11
β’
((β―βπ) =
2 β (β―βπ)
β 0) |
10 | | hasheq0 14328 |
. . . . . . . . . . . . 13
β’ (π β V β
((β―βπ) = 0
β π =
β
)) |
11 | 10 | elv 3479 |
. . . . . . . . . . . 12
β’
((β―βπ) =
0 β π =
β
) |
12 | 11 | necon3bii 2992 |
. . . . . . . . . . 11
β’
((β―βπ)
β 0 β π β
β
) |
13 | 9, 12 | sylib 217 |
. . . . . . . . . 10
β’
((β―βπ) =
2 β π β
β
) |
14 | 13 | anim2i 616 |
. . . . . . . . 9
β’ ((π(CyclesβπΊ)π β§ (β―βπ) = 2) β (π(CyclesβπΊ)π β§ π β β
)) |
15 | 14 | 2eximi 1837 |
. . . . . . . 8
β’
(βπβπ(π(CyclesβπΊ)π β§ (β―βπ) = 2) β βπβπ(π(CyclesβπΊ)π β§ π β β
)) |
16 | 6, 15 | syl 17 |
. . . . . . 7
β’ ((πΊ β UMGraph β§
βπ β dom
(iEdgβπΊ)βπ β dom (iEdgβπΊ)(((iEdgβπΊ)βπ) = ((iEdgβπΊ)βπ) β§ π β π)) β βπβπ(π(CyclesβπΊ)π β§ π β β
)) |
17 | 16 | ex 412 |
. . . . . 6
β’ (πΊ β UMGraph β
(βπ β dom
(iEdgβπΊ)βπ β dom (iEdgβπΊ)(((iEdgβπΊ)βπ) = ((iEdgβπΊ)βπ) β§ π β π) β βπβπ(π(CyclesβπΊ)π β§ π β β
))) |
18 | 17 | con3d 152 |
. . . . 5
β’ (πΊ β UMGraph β (Β¬
βπβπ(π(CyclesβπΊ)π β§ π β β
) β Β¬ βπ β dom (iEdgβπΊ)βπ β dom (iEdgβπΊ)(((iEdgβπΊ)βπ) = ((iEdgβπΊ)βπ) β§ π β π))) |
19 | 18 | adantr 480 |
. . . 4
β’ ((πΊ β UMGraph β§ πΊ β AcyclicGraph) β
(Β¬ βπβπ(π(CyclesβπΊ)π β§ π β β
) β Β¬ βπ β dom (iEdgβπΊ)βπ β dom (iEdgβπΊ)(((iEdgβπΊ)βπ) = ((iEdgβπΊ)βπ) β§ π β π))) |
20 | 5, 19 | mpd 15 |
. . 3
β’ ((πΊ β UMGraph β§ πΊ β AcyclicGraph) β
Β¬ βπ β dom
(iEdgβπΊ)βπ β dom (iEdgβπΊ)(((iEdgβπΊ)βπ) = ((iEdgβπΊ)βπ) β§ π β π)) |
21 | | dff15 34382 |
. . . 4
β’
((iEdgβπΊ):dom
(iEdgβπΊ)β1-1β{π₯ β π« (VtxβπΊ) β£ (β―βπ₯) = 2} β ((iEdgβπΊ):dom (iEdgβπΊ)βΆ{π₯ β π« (VtxβπΊ) β£ (β―βπ₯) = 2} β§ Β¬ βπ β dom (iEdgβπΊ)βπ β dom (iEdgβπΊ)(((iEdgβπΊ)βπ) = ((iEdgβπΊ)βπ) β§ π β π))) |
22 | 21 | biimpri 227 |
. . 3
β’
(((iEdgβπΊ):dom
(iEdgβπΊ)βΆ{π₯ β π« (VtxβπΊ) β£ (β―βπ₯) = 2} β§ Β¬ βπ β dom (iEdgβπΊ)βπ β dom (iEdgβπΊ)(((iEdgβπΊ)βπ) = ((iEdgβπΊ)βπ) β§ π β π)) β (iEdgβπΊ):dom (iEdgβπΊ)β1-1β{π₯ β π« (VtxβπΊ) β£ (β―βπ₯) = 2}) |
23 | 3, 20, 22 | syl2an2r 682 |
. 2
β’ ((πΊ β UMGraph β§ πΊ β AcyclicGraph) β
(iEdgβπΊ):dom
(iEdgβπΊ)β1-1β{π₯ β π« (VtxβπΊ) β£ (β―βπ₯) = 2}) |
24 | 1, 2 | isusgrs 28680 |
. . . 4
β’ (πΊ β UMGraph β (πΊ β USGraph β
(iEdgβπΊ):dom
(iEdgβπΊ)β1-1β{π₯ β π« (VtxβπΊ) β£ (β―βπ₯) = 2})) |
25 | 24 | biimprd 247 |
. . 3
β’ (πΊ β UMGraph β
((iEdgβπΊ):dom
(iEdgβπΊ)β1-1β{π₯ β π« (VtxβπΊ) β£ (β―βπ₯) = 2} β πΊ β USGraph)) |
26 | 25 | adantr 480 |
. 2
β’ ((πΊ β UMGraph β§ πΊ β AcyclicGraph) β
((iEdgβπΊ):dom
(iEdgβπΊ)β1-1β{π₯ β π« (VtxβπΊ) β£ (β―βπ₯) = 2} β πΊ β USGraph)) |
27 | 23, 26 | mpd 15 |
1
β’ ((πΊ β UMGraph β§ πΊ β AcyclicGraph) β
πΊ β
USGraph) |