Metamath Proof Explorer


Theorem upgrimpths

Description: Graph isomorphisms between simple pseudographs map paths onto paths. (Contributed by AV, 31-Oct-2025)

Ref Expression
Hypotheses upgrimwlk.i 𝐼 = ( iEdg ‘ 𝐺 )
upgrimwlk.j 𝐽 = ( iEdg ‘ 𝐻 )
upgrimwlk.g ( 𝜑𝐺 ∈ USPGraph )
upgrimwlk.h ( 𝜑𝐻 ∈ USPGraph )
upgrimwlk.n ( 𝜑𝑁 ∈ ( 𝐺 GraphIso 𝐻 ) )
upgrimwlk.e 𝐸 = ( 𝑥 ∈ dom 𝐹 ↦ ( 𝐽 ‘ ( 𝑁 “ ( 𝐼 ‘ ( 𝐹𝑥 ) ) ) ) )
upgrimpths.p ( 𝜑𝐹 ( Paths ‘ 𝐺 ) 𝑃 )
Assertion upgrimpths ( 𝜑𝐸 ( Paths ‘ 𝐻 ) ( 𝑁𝑃 ) )

Proof

Step Hyp Ref Expression
1 upgrimwlk.i 𝐼 = ( iEdg ‘ 𝐺 )
2 upgrimwlk.j 𝐽 = ( iEdg ‘ 𝐻 )
3 upgrimwlk.g ( 𝜑𝐺 ∈ USPGraph )
4 upgrimwlk.h ( 𝜑𝐻 ∈ USPGraph )
5 upgrimwlk.n ( 𝜑𝑁 ∈ ( 𝐺 GraphIso 𝐻 ) )
6 upgrimwlk.e 𝐸 = ( 𝑥 ∈ dom 𝐹 ↦ ( 𝐽 ‘ ( 𝑁 “ ( 𝐼 ‘ ( 𝐹𝑥 ) ) ) ) )
7 upgrimpths.p ( 𝜑𝐹 ( Paths ‘ 𝐺 ) 𝑃 )
8 pthistrl ( 𝐹 ( Paths ‘ 𝐺 ) 𝑃𝐹 ( Trails ‘ 𝐺 ) 𝑃 )
9 7 8 syl ( 𝜑𝐹 ( Trails ‘ 𝐺 ) 𝑃 )
10 1 2 3 4 5 6 9 upgrimtrls ( 𝜑𝐸 ( Trails ‘ 𝐻 ) ( 𝑁𝑃 ) )
11 1 2 3 4 5 6 7 upgrimpthslem1 ( 𝜑 → Fun ( ( 𝑁𝑃 ) ↾ ( 1 ..^ ( ♯ ‘ 𝐹 ) ) ) )
12 pthiswlk ( 𝐹 ( Paths ‘ 𝐺 ) 𝑃𝐹 ( Walks ‘ 𝐺 ) 𝑃 )
13 1 wlkf ( 𝐹 ( Walks ‘ 𝐺 ) 𝑃𝐹 ∈ Word dom 𝐼 )
14 7 12 13 3syl ( 𝜑𝐹 ∈ Word dom 𝐼 )
15 eqid ( Vtx ‘ 𝐺 ) = ( Vtx ‘ 𝐺 )
16 15 wlkp ( 𝐹 ( Walks ‘ 𝐺 ) 𝑃𝑃 : ( 0 ... ( ♯ ‘ 𝐹 ) ) ⟶ ( Vtx ‘ 𝐺 ) )
17 7 12 16 3syl ( 𝜑𝑃 : ( 0 ... ( ♯ ‘ 𝐹 ) ) ⟶ ( Vtx ‘ 𝐺 ) )
18 1 2 3 4 5 6 14 17 upgrimwlklem4 ( 𝜑 → ( 𝑁𝑃 ) : ( 0 ... ( ♯ ‘ 𝐸 ) ) ⟶ ( Vtx ‘ 𝐻 ) )
19 18 ffnd ( 𝜑 → ( 𝑁𝑃 ) Fn ( 0 ... ( ♯ ‘ 𝐸 ) ) )
20 1 2 3 4 5 6 14 upgrimwlklem1 ( 𝜑 → ( ♯ ‘ 𝐸 ) = ( ♯ ‘ 𝐹 ) )
21 wlkcl ( 𝐹 ( Walks ‘ 𝐺 ) 𝑃 → ( ♯ ‘ 𝐹 ) ∈ ℕ0 )
22 7 12 21 3syl ( 𝜑 → ( ♯ ‘ 𝐹 ) ∈ ℕ0 )
23 20 22 eqeltrd ( 𝜑 → ( ♯ ‘ 𝐸 ) ∈ ℕ0 )
24 0elfz ( ( ♯ ‘ 𝐸 ) ∈ ℕ0 → 0 ∈ ( 0 ... ( ♯ ‘ 𝐸 ) ) )
25 23 24 syl ( 𝜑 → 0 ∈ ( 0 ... ( ♯ ‘ 𝐸 ) ) )
26 nn0fz0 ( ( ♯ ‘ 𝐹 ) ∈ ℕ0 ↔ ( ♯ ‘ 𝐹 ) ∈ ( 0 ... ( ♯ ‘ 𝐹 ) ) )
27 22 26 sylib ( 𝜑 → ( ♯ ‘ 𝐹 ) ∈ ( 0 ... ( ♯ ‘ 𝐹 ) ) )
28 20 oveq2d ( 𝜑 → ( 0 ... ( ♯ ‘ 𝐸 ) ) = ( 0 ... ( ♯ ‘ 𝐹 ) ) )
29 27 28 eleqtrrd ( 𝜑 → ( ♯ ‘ 𝐹 ) ∈ ( 0 ... ( ♯ ‘ 𝐸 ) ) )
30 fnimapr ( ( ( 𝑁𝑃 ) Fn ( 0 ... ( ♯ ‘ 𝐸 ) ) ∧ 0 ∈ ( 0 ... ( ♯ ‘ 𝐸 ) ) ∧ ( ♯ ‘ 𝐹 ) ∈ ( 0 ... ( ♯ ‘ 𝐸 ) ) ) → ( ( 𝑁𝑃 ) “ { 0 , ( ♯ ‘ 𝐹 ) } ) = { ( ( 𝑁𝑃 ) ‘ 0 ) , ( ( 𝑁𝑃 ) ‘ ( ♯ ‘ 𝐹 ) ) } )
31 19 25 29 30 syl3anc ( 𝜑 → ( ( 𝑁𝑃 ) “ { 0 , ( ♯ ‘ 𝐹 ) } ) = { ( ( 𝑁𝑃 ) ‘ 0 ) , ( ( 𝑁𝑃 ) ‘ ( ♯ ‘ 𝐹 ) ) } )
32 31 eleq2d ( 𝜑 → ( 𝑥 ∈ ( ( 𝑁𝑃 ) “ { 0 , ( ♯ ‘ 𝐹 ) } ) ↔ 𝑥 ∈ { ( ( 𝑁𝑃 ) ‘ 0 ) , ( ( 𝑁𝑃 ) ‘ ( ♯ ‘ 𝐹 ) ) } ) )
33 vex 𝑥 ∈ V
34 33 elpr ( 𝑥 ∈ { ( ( 𝑁𝑃 ) ‘ 0 ) , ( ( 𝑁𝑃 ) ‘ ( ♯ ‘ 𝐹 ) ) } ↔ ( 𝑥 = ( ( 𝑁𝑃 ) ‘ 0 ) ∨ 𝑥 = ( ( 𝑁𝑃 ) ‘ ( ♯ ‘ 𝐹 ) ) ) )
35 32 34 bitrdi ( 𝜑 → ( 𝑥 ∈ ( ( 𝑁𝑃 ) “ { 0 , ( ♯ ‘ 𝐹 ) } ) ↔ ( 𝑥 = ( ( 𝑁𝑃 ) ‘ 0 ) ∨ 𝑥 = ( ( 𝑁𝑃 ) ‘ ( ♯ ‘ 𝐹 ) ) ) ) )
36 1 2 3 4 5 6 7 upgrimpthslem2 ( ( 𝜑𝑦 ∈ ( 1 ..^ ( ♯ ‘ 𝐹 ) ) ) → ( ¬ ( ( 𝑁𝑃 ) ‘ 𝑦 ) = ( ( 𝑁𝑃 ) ‘ 0 ) ∧ ¬ ( ( 𝑁𝑃 ) ‘ 𝑦 ) = ( ( 𝑁𝑃 ) ‘ ( ♯ ‘ 𝐹 ) ) ) )
37 36 simpld ( ( 𝜑𝑦 ∈ ( 1 ..^ ( ♯ ‘ 𝐹 ) ) ) → ¬ ( ( 𝑁𝑃 ) ‘ 𝑦 ) = ( ( 𝑁𝑃 ) ‘ 0 ) )
38 eqeq2 ( 𝑥 = ( ( 𝑁𝑃 ) ‘ 0 ) → ( ( ( 𝑁𝑃 ) ‘ 𝑦 ) = 𝑥 ↔ ( ( 𝑁𝑃 ) ‘ 𝑦 ) = ( ( 𝑁𝑃 ) ‘ 0 ) ) )
39 38 notbid ( 𝑥 = ( ( 𝑁𝑃 ) ‘ 0 ) → ( ¬ ( ( 𝑁𝑃 ) ‘ 𝑦 ) = 𝑥 ↔ ¬ ( ( 𝑁𝑃 ) ‘ 𝑦 ) = ( ( 𝑁𝑃 ) ‘ 0 ) ) )
40 37 39 syl5ibrcom ( ( 𝜑𝑦 ∈ ( 1 ..^ ( ♯ ‘ 𝐹 ) ) ) → ( 𝑥 = ( ( 𝑁𝑃 ) ‘ 0 ) → ¬ ( ( 𝑁𝑃 ) ‘ 𝑦 ) = 𝑥 ) )
41 36 simprd ( ( 𝜑𝑦 ∈ ( 1 ..^ ( ♯ ‘ 𝐹 ) ) ) → ¬ ( ( 𝑁𝑃 ) ‘ 𝑦 ) = ( ( 𝑁𝑃 ) ‘ ( ♯ ‘ 𝐹 ) ) )
42 eqeq2 ( 𝑥 = ( ( 𝑁𝑃 ) ‘ ( ♯ ‘ 𝐹 ) ) → ( ( ( 𝑁𝑃 ) ‘ 𝑦 ) = 𝑥 ↔ ( ( 𝑁𝑃 ) ‘ 𝑦 ) = ( ( 𝑁𝑃 ) ‘ ( ♯ ‘ 𝐹 ) ) ) )
43 42 notbid ( 𝑥 = ( ( 𝑁𝑃 ) ‘ ( ♯ ‘ 𝐹 ) ) → ( ¬ ( ( 𝑁𝑃 ) ‘ 𝑦 ) = 𝑥 ↔ ¬ ( ( 𝑁𝑃 ) ‘ 𝑦 ) = ( ( 𝑁𝑃 ) ‘ ( ♯ ‘ 𝐹 ) ) ) )
44 41 43 syl5ibrcom ( ( 𝜑𝑦 ∈ ( 1 ..^ ( ♯ ‘ 𝐹 ) ) ) → ( 𝑥 = ( ( 𝑁𝑃 ) ‘ ( ♯ ‘ 𝐹 ) ) → ¬ ( ( 𝑁𝑃 ) ‘ 𝑦 ) = 𝑥 ) )
45 40 44 jaod ( ( 𝜑𝑦 ∈ ( 1 ..^ ( ♯ ‘ 𝐹 ) ) ) → ( ( 𝑥 = ( ( 𝑁𝑃 ) ‘ 0 ) ∨ 𝑥 = ( ( 𝑁𝑃 ) ‘ ( ♯ ‘ 𝐹 ) ) ) → ¬ ( ( 𝑁𝑃 ) ‘ 𝑦 ) = 𝑥 ) )
46 45 impancom ( ( 𝜑 ∧ ( 𝑥 = ( ( 𝑁𝑃 ) ‘ 0 ) ∨ 𝑥 = ( ( 𝑁𝑃 ) ‘ ( ♯ ‘ 𝐹 ) ) ) ) → ( 𝑦 ∈ ( 1 ..^ ( ♯ ‘ 𝐹 ) ) → ¬ ( ( 𝑁𝑃 ) ‘ 𝑦 ) = 𝑥 ) )
47 46 imp ( ( ( 𝜑 ∧ ( 𝑥 = ( ( 𝑁𝑃 ) ‘ 0 ) ∨ 𝑥 = ( ( 𝑁𝑃 ) ‘ ( ♯ ‘ 𝐹 ) ) ) ) ∧ 𝑦 ∈ ( 1 ..^ ( ♯ ‘ 𝐹 ) ) ) → ¬ ( ( 𝑁𝑃 ) ‘ 𝑦 ) = 𝑥 )
48 47 nrexdv ( ( 𝜑 ∧ ( 𝑥 = ( ( 𝑁𝑃 ) ‘ 0 ) ∨ 𝑥 = ( ( 𝑁𝑃 ) ‘ ( ♯ ‘ 𝐹 ) ) ) ) → ¬ ∃ 𝑦 ∈ ( 1 ..^ ( ♯ ‘ 𝐹 ) ) ( ( 𝑁𝑃 ) ‘ 𝑦 ) = 𝑥 )
49 20 eqcomd ( 𝜑 → ( ♯ ‘ 𝐹 ) = ( ♯ ‘ 𝐸 ) )
50 49 oveq2d ( 𝜑 → ( 0 ... ( ♯ ‘ 𝐹 ) ) = ( 0 ... ( ♯ ‘ 𝐸 ) ) )
51 50 feq2d ( 𝜑 → ( ( 𝑁𝑃 ) : ( 0 ... ( ♯ ‘ 𝐹 ) ) ⟶ ( Vtx ‘ 𝐻 ) ↔ ( 𝑁𝑃 ) : ( 0 ... ( ♯ ‘ 𝐸 ) ) ⟶ ( Vtx ‘ 𝐻 ) ) )
52 18 51 mpbird ( 𝜑 → ( 𝑁𝑃 ) : ( 0 ... ( ♯ ‘ 𝐹 ) ) ⟶ ( Vtx ‘ 𝐻 ) )
53 52 ffnd ( 𝜑 → ( 𝑁𝑃 ) Fn ( 0 ... ( ♯ ‘ 𝐹 ) ) )
54 53 adantr ( ( 𝜑 ∧ ( 𝑥 = ( ( 𝑁𝑃 ) ‘ 0 ) ∨ 𝑥 = ( ( 𝑁𝑃 ) ‘ ( ♯ ‘ 𝐹 ) ) ) ) → ( 𝑁𝑃 ) Fn ( 0 ... ( ♯ ‘ 𝐹 ) ) )
55 fzo0ss1 ( 1 ..^ ( ♯ ‘ 𝐹 ) ) ⊆ ( 0 ..^ ( ♯ ‘ 𝐹 ) )
56 fzossfz ( 0 ..^ ( ♯ ‘ 𝐹 ) ) ⊆ ( 0 ... ( ♯ ‘ 𝐹 ) )
57 55 56 sstri ( 1 ..^ ( ♯ ‘ 𝐹 ) ) ⊆ ( 0 ... ( ♯ ‘ 𝐹 ) )
58 57 a1i ( ( 𝜑 ∧ ( 𝑥 = ( ( 𝑁𝑃 ) ‘ 0 ) ∨ 𝑥 = ( ( 𝑁𝑃 ) ‘ ( ♯ ‘ 𝐹 ) ) ) ) → ( 1 ..^ ( ♯ ‘ 𝐹 ) ) ⊆ ( 0 ... ( ♯ ‘ 𝐹 ) ) )
59 54 58 fvelimabd ( ( 𝜑 ∧ ( 𝑥 = ( ( 𝑁𝑃 ) ‘ 0 ) ∨ 𝑥 = ( ( 𝑁𝑃 ) ‘ ( ♯ ‘ 𝐹 ) ) ) ) → ( 𝑥 ∈ ( ( 𝑁𝑃 ) “ ( 1 ..^ ( ♯ ‘ 𝐹 ) ) ) ↔ ∃ 𝑦 ∈ ( 1 ..^ ( ♯ ‘ 𝐹 ) ) ( ( 𝑁𝑃 ) ‘ 𝑦 ) = 𝑥 ) )
60 48 59 mtbird ( ( 𝜑 ∧ ( 𝑥 = ( ( 𝑁𝑃 ) ‘ 0 ) ∨ 𝑥 = ( ( 𝑁𝑃 ) ‘ ( ♯ ‘ 𝐹 ) ) ) ) → ¬ 𝑥 ∈ ( ( 𝑁𝑃 ) “ ( 1 ..^ ( ♯ ‘ 𝐹 ) ) ) )
61 60 ex ( 𝜑 → ( ( 𝑥 = ( ( 𝑁𝑃 ) ‘ 0 ) ∨ 𝑥 = ( ( 𝑁𝑃 ) ‘ ( ♯ ‘ 𝐹 ) ) ) → ¬ 𝑥 ∈ ( ( 𝑁𝑃 ) “ ( 1 ..^ ( ♯ ‘ 𝐹 ) ) ) ) )
62 35 61 sylbid ( 𝜑 → ( 𝑥 ∈ ( ( 𝑁𝑃 ) “ { 0 , ( ♯ ‘ 𝐹 ) } ) → ¬ 𝑥 ∈ ( ( 𝑁𝑃 ) “ ( 1 ..^ ( ♯ ‘ 𝐹 ) ) ) ) )
63 62 ralrimiv ( 𝜑 → ∀ 𝑥 ∈ ( ( 𝑁𝑃 ) “ { 0 , ( ♯ ‘ 𝐹 ) } ) ¬ 𝑥 ∈ ( ( 𝑁𝑃 ) “ ( 1 ..^ ( ♯ ‘ 𝐹 ) ) ) )
64 disj ( ( ( ( 𝑁𝑃 ) “ { 0 , ( ♯ ‘ 𝐹 ) } ) ∩ ( ( 𝑁𝑃 ) “ ( 1 ..^ ( ♯ ‘ 𝐹 ) ) ) ) = ∅ ↔ ∀ 𝑥 ∈ ( ( 𝑁𝑃 ) “ { 0 , ( ♯ ‘ 𝐹 ) } ) ¬ 𝑥 ∈ ( ( 𝑁𝑃 ) “ ( 1 ..^ ( ♯ ‘ 𝐹 ) ) ) )
65 63 64 sylibr ( 𝜑 → ( ( ( 𝑁𝑃 ) “ { 0 , ( ♯ ‘ 𝐹 ) } ) ∩ ( ( 𝑁𝑃 ) “ ( 1 ..^ ( ♯ ‘ 𝐹 ) ) ) ) = ∅ )
66 20 oveq2d ( 𝜑 → ( 1 ..^ ( ♯ ‘ 𝐸 ) ) = ( 1 ..^ ( ♯ ‘ 𝐹 ) ) )
67 66 reseq2d ( 𝜑 → ( ( 𝑁𝑃 ) ↾ ( 1 ..^ ( ♯ ‘ 𝐸 ) ) ) = ( ( 𝑁𝑃 ) ↾ ( 1 ..^ ( ♯ ‘ 𝐹 ) ) ) )
68 67 cnveqd ( 𝜑 ( ( 𝑁𝑃 ) ↾ ( 1 ..^ ( ♯ ‘ 𝐸 ) ) ) = ( ( 𝑁𝑃 ) ↾ ( 1 ..^ ( ♯ ‘ 𝐹 ) ) ) )
69 68 funeqd ( 𝜑 → ( Fun ( ( 𝑁𝑃 ) ↾ ( 1 ..^ ( ♯ ‘ 𝐸 ) ) ) ↔ Fun ( ( 𝑁𝑃 ) ↾ ( 1 ..^ ( ♯ ‘ 𝐹 ) ) ) ) )
70 preq2 ( ( ♯ ‘ 𝐸 ) = ( ♯ ‘ 𝐹 ) → { 0 , ( ♯ ‘ 𝐸 ) } = { 0 , ( ♯ ‘ 𝐹 ) } )
71 70 imaeq2d ( ( ♯ ‘ 𝐸 ) = ( ♯ ‘ 𝐹 ) → ( ( 𝑁𝑃 ) “ { 0 , ( ♯ ‘ 𝐸 ) } ) = ( ( 𝑁𝑃 ) “ { 0 , ( ♯ ‘ 𝐹 ) } ) )
72 oveq2 ( ( ♯ ‘ 𝐸 ) = ( ♯ ‘ 𝐹 ) → ( 1 ..^ ( ♯ ‘ 𝐸 ) ) = ( 1 ..^ ( ♯ ‘ 𝐹 ) ) )
73 72 imaeq2d ( ( ♯ ‘ 𝐸 ) = ( ♯ ‘ 𝐹 ) → ( ( 𝑁𝑃 ) “ ( 1 ..^ ( ♯ ‘ 𝐸 ) ) ) = ( ( 𝑁𝑃 ) “ ( 1 ..^ ( ♯ ‘ 𝐹 ) ) ) )
74 71 73 ineq12d ( ( ♯ ‘ 𝐸 ) = ( ♯ ‘ 𝐹 ) → ( ( ( 𝑁𝑃 ) “ { 0 , ( ♯ ‘ 𝐸 ) } ) ∩ ( ( 𝑁𝑃 ) “ ( 1 ..^ ( ♯ ‘ 𝐸 ) ) ) ) = ( ( ( 𝑁𝑃 ) “ { 0 , ( ♯ ‘ 𝐹 ) } ) ∩ ( ( 𝑁𝑃 ) “ ( 1 ..^ ( ♯ ‘ 𝐹 ) ) ) ) )
75 74 eqeq1d ( ( ♯ ‘ 𝐸 ) = ( ♯ ‘ 𝐹 ) → ( ( ( ( 𝑁𝑃 ) “ { 0 , ( ♯ ‘ 𝐸 ) } ) ∩ ( ( 𝑁𝑃 ) “ ( 1 ..^ ( ♯ ‘ 𝐸 ) ) ) ) = ∅ ↔ ( ( ( 𝑁𝑃 ) “ { 0 , ( ♯ ‘ 𝐹 ) } ) ∩ ( ( 𝑁𝑃 ) “ ( 1 ..^ ( ♯ ‘ 𝐹 ) ) ) ) = ∅ ) )
76 20 75 syl ( 𝜑 → ( ( ( ( 𝑁𝑃 ) “ { 0 , ( ♯ ‘ 𝐸 ) } ) ∩ ( ( 𝑁𝑃 ) “ ( 1 ..^ ( ♯ ‘ 𝐸 ) ) ) ) = ∅ ↔ ( ( ( 𝑁𝑃 ) “ { 0 , ( ♯ ‘ 𝐹 ) } ) ∩ ( ( 𝑁𝑃 ) “ ( 1 ..^ ( ♯ ‘ 𝐹 ) ) ) ) = ∅ ) )
77 69 76 3anbi23d ( 𝜑 → ( ( 𝐸 ( Trails ‘ 𝐻 ) ( 𝑁𝑃 ) ∧ Fun ( ( 𝑁𝑃 ) ↾ ( 1 ..^ ( ♯ ‘ 𝐸 ) ) ) ∧ ( ( ( 𝑁𝑃 ) “ { 0 , ( ♯ ‘ 𝐸 ) } ) ∩ ( ( 𝑁𝑃 ) “ ( 1 ..^ ( ♯ ‘ 𝐸 ) ) ) ) = ∅ ) ↔ ( 𝐸 ( Trails ‘ 𝐻 ) ( 𝑁𝑃 ) ∧ Fun ( ( 𝑁𝑃 ) ↾ ( 1 ..^ ( ♯ ‘ 𝐹 ) ) ) ∧ ( ( ( 𝑁𝑃 ) “ { 0 , ( ♯ ‘ 𝐹 ) } ) ∩ ( ( 𝑁𝑃 ) “ ( 1 ..^ ( ♯ ‘ 𝐹 ) ) ) ) = ∅ ) ) )
78 10 11 65 77 mpbir3and ( 𝜑 → ( 𝐸 ( Trails ‘ 𝐻 ) ( 𝑁𝑃 ) ∧ Fun ( ( 𝑁𝑃 ) ↾ ( 1 ..^ ( ♯ ‘ 𝐸 ) ) ) ∧ ( ( ( 𝑁𝑃 ) “ { 0 , ( ♯ ‘ 𝐸 ) } ) ∩ ( ( 𝑁𝑃 ) “ ( 1 ..^ ( ♯ ‘ 𝐸 ) ) ) ) = ∅ ) )
79 ispth ( 𝐸 ( Paths ‘ 𝐻 ) ( 𝑁𝑃 ) ↔ ( 𝐸 ( Trails ‘ 𝐻 ) ( 𝑁𝑃 ) ∧ Fun ( ( 𝑁𝑃 ) ↾ ( 1 ..^ ( ♯ ‘ 𝐸 ) ) ) ∧ ( ( ( 𝑁𝑃 ) “ { 0 , ( ♯ ‘ 𝐸 ) } ) ∩ ( ( 𝑁𝑃 ) “ ( 1 ..^ ( ♯ ‘ 𝐸 ) ) ) ) = ∅ ) )
80 78 79 sylibr ( 𝜑𝐸 ( Paths ‘ 𝐻 ) ( 𝑁𝑃 ) )