Step |
Hyp |
Ref |
Expression |
1 |
|
1hevtxdg0.i |
⊢ ( 𝜑 → ( iEdg ‘ 𝐺 ) = { 〈 𝐴 , 𝐸 〉 } ) |
2 |
|
1hevtxdg0.v |
⊢ ( 𝜑 → ( Vtx ‘ 𝐺 ) = 𝑉 ) |
3 |
|
1hevtxdg0.a |
⊢ ( 𝜑 → 𝐴 ∈ 𝑋 ) |
4 |
|
1hevtxdg0.d |
⊢ ( 𝜑 → 𝐷 ∈ 𝑉 ) |
5 |
|
1hevtxdg1.e |
⊢ ( 𝜑 → 𝐸 ∈ 𝒫 𝑉 ) |
6 |
|
1hevtxdg1.n |
⊢ ( 𝜑 → 𝐷 ∈ 𝐸 ) |
7 |
|
1hevtxdg1.l |
⊢ ( 𝜑 → 2 ≤ ( ♯ ‘ 𝐸 ) ) |
8 |
1
|
dmeqd |
⊢ ( 𝜑 → dom ( iEdg ‘ 𝐺 ) = dom { 〈 𝐴 , 𝐸 〉 } ) |
9 |
|
dmsnopg |
⊢ ( 𝐸 ∈ 𝒫 𝑉 → dom { 〈 𝐴 , 𝐸 〉 } = { 𝐴 } ) |
10 |
5 9
|
syl |
⊢ ( 𝜑 → dom { 〈 𝐴 , 𝐸 〉 } = { 𝐴 } ) |
11 |
8 10
|
eqtrd |
⊢ ( 𝜑 → dom ( iEdg ‘ 𝐺 ) = { 𝐴 } ) |
12 |
|
fveq2 |
⊢ ( 𝑥 = 𝐸 → ( ♯ ‘ 𝑥 ) = ( ♯ ‘ 𝐸 ) ) |
13 |
12
|
breq2d |
⊢ ( 𝑥 = 𝐸 → ( 2 ≤ ( ♯ ‘ 𝑥 ) ↔ 2 ≤ ( ♯ ‘ 𝐸 ) ) ) |
14 |
2
|
pweqd |
⊢ ( 𝜑 → 𝒫 ( Vtx ‘ 𝐺 ) = 𝒫 𝑉 ) |
15 |
5 14
|
eleqtrrd |
⊢ ( 𝜑 → 𝐸 ∈ 𝒫 ( Vtx ‘ 𝐺 ) ) |
16 |
13 15 7
|
elrabd |
⊢ ( 𝜑 → 𝐸 ∈ { 𝑥 ∈ 𝒫 ( Vtx ‘ 𝐺 ) ∣ 2 ≤ ( ♯ ‘ 𝑥 ) } ) |
17 |
3 16
|
fsnd |
⊢ ( 𝜑 → { 〈 𝐴 , 𝐸 〉 } : { 𝐴 } ⟶ { 𝑥 ∈ 𝒫 ( Vtx ‘ 𝐺 ) ∣ 2 ≤ ( ♯ ‘ 𝑥 ) } ) |
18 |
17
|
adantr |
⊢ ( ( 𝜑 ∧ dom ( iEdg ‘ 𝐺 ) = { 𝐴 } ) → { 〈 𝐴 , 𝐸 〉 } : { 𝐴 } ⟶ { 𝑥 ∈ 𝒫 ( Vtx ‘ 𝐺 ) ∣ 2 ≤ ( ♯ ‘ 𝑥 ) } ) |
19 |
1
|
adantr |
⊢ ( ( 𝜑 ∧ dom ( iEdg ‘ 𝐺 ) = { 𝐴 } ) → ( iEdg ‘ 𝐺 ) = { 〈 𝐴 , 𝐸 〉 } ) |
20 |
|
simpr |
⊢ ( ( 𝜑 ∧ dom ( iEdg ‘ 𝐺 ) = { 𝐴 } ) → dom ( iEdg ‘ 𝐺 ) = { 𝐴 } ) |
21 |
19 20
|
feq12d |
⊢ ( ( 𝜑 ∧ dom ( iEdg ‘ 𝐺 ) = { 𝐴 } ) → ( ( iEdg ‘ 𝐺 ) : dom ( iEdg ‘ 𝐺 ) ⟶ { 𝑥 ∈ 𝒫 ( Vtx ‘ 𝐺 ) ∣ 2 ≤ ( ♯ ‘ 𝑥 ) } ↔ { 〈 𝐴 , 𝐸 〉 } : { 𝐴 } ⟶ { 𝑥 ∈ 𝒫 ( Vtx ‘ 𝐺 ) ∣ 2 ≤ ( ♯ ‘ 𝑥 ) } ) ) |
22 |
18 21
|
mpbird |
⊢ ( ( 𝜑 ∧ dom ( iEdg ‘ 𝐺 ) = { 𝐴 } ) → ( iEdg ‘ 𝐺 ) : dom ( iEdg ‘ 𝐺 ) ⟶ { 𝑥 ∈ 𝒫 ( Vtx ‘ 𝐺 ) ∣ 2 ≤ ( ♯ ‘ 𝑥 ) } ) |
23 |
4 2
|
eleqtrrd |
⊢ ( 𝜑 → 𝐷 ∈ ( Vtx ‘ 𝐺 ) ) |
24 |
23
|
adantr |
⊢ ( ( 𝜑 ∧ dom ( iEdg ‘ 𝐺 ) = { 𝐴 } ) → 𝐷 ∈ ( Vtx ‘ 𝐺 ) ) |
25 |
|
eqid |
⊢ ( Vtx ‘ 𝐺 ) = ( Vtx ‘ 𝐺 ) |
26 |
|
eqid |
⊢ ( iEdg ‘ 𝐺 ) = ( iEdg ‘ 𝐺 ) |
27 |
|
eqid |
⊢ dom ( iEdg ‘ 𝐺 ) = dom ( iEdg ‘ 𝐺 ) |
28 |
|
eqid |
⊢ ( VtxDeg ‘ 𝐺 ) = ( VtxDeg ‘ 𝐺 ) |
29 |
25 26 27 28
|
vtxdlfgrval |
⊢ ( ( ( iEdg ‘ 𝐺 ) : dom ( iEdg ‘ 𝐺 ) ⟶ { 𝑥 ∈ 𝒫 ( Vtx ‘ 𝐺 ) ∣ 2 ≤ ( ♯ ‘ 𝑥 ) } ∧ 𝐷 ∈ ( Vtx ‘ 𝐺 ) ) → ( ( VtxDeg ‘ 𝐺 ) ‘ 𝐷 ) = ( ♯ ‘ { 𝑥 ∈ dom ( iEdg ‘ 𝐺 ) ∣ 𝐷 ∈ ( ( iEdg ‘ 𝐺 ) ‘ 𝑥 ) } ) ) |
30 |
22 24 29
|
syl2anc |
⊢ ( ( 𝜑 ∧ dom ( iEdg ‘ 𝐺 ) = { 𝐴 } ) → ( ( VtxDeg ‘ 𝐺 ) ‘ 𝐷 ) = ( ♯ ‘ { 𝑥 ∈ dom ( iEdg ‘ 𝐺 ) ∣ 𝐷 ∈ ( ( iEdg ‘ 𝐺 ) ‘ 𝑥 ) } ) ) |
31 |
|
rabeq |
⊢ ( dom ( iEdg ‘ 𝐺 ) = { 𝐴 } → { 𝑥 ∈ dom ( iEdg ‘ 𝐺 ) ∣ 𝐷 ∈ ( ( iEdg ‘ 𝐺 ) ‘ 𝑥 ) } = { 𝑥 ∈ { 𝐴 } ∣ 𝐷 ∈ ( ( iEdg ‘ 𝐺 ) ‘ 𝑥 ) } ) |
32 |
31
|
adantl |
⊢ ( ( 𝜑 ∧ dom ( iEdg ‘ 𝐺 ) = { 𝐴 } ) → { 𝑥 ∈ dom ( iEdg ‘ 𝐺 ) ∣ 𝐷 ∈ ( ( iEdg ‘ 𝐺 ) ‘ 𝑥 ) } = { 𝑥 ∈ { 𝐴 } ∣ 𝐷 ∈ ( ( iEdg ‘ 𝐺 ) ‘ 𝑥 ) } ) |
33 |
32
|
fveq2d |
⊢ ( ( 𝜑 ∧ dom ( iEdg ‘ 𝐺 ) = { 𝐴 } ) → ( ♯ ‘ { 𝑥 ∈ dom ( iEdg ‘ 𝐺 ) ∣ 𝐷 ∈ ( ( iEdg ‘ 𝐺 ) ‘ 𝑥 ) } ) = ( ♯ ‘ { 𝑥 ∈ { 𝐴 } ∣ 𝐷 ∈ ( ( iEdg ‘ 𝐺 ) ‘ 𝑥 ) } ) ) |
34 |
|
fveq2 |
⊢ ( 𝑥 = 𝐴 → ( ( iEdg ‘ 𝐺 ) ‘ 𝑥 ) = ( ( iEdg ‘ 𝐺 ) ‘ 𝐴 ) ) |
35 |
34
|
eleq2d |
⊢ ( 𝑥 = 𝐴 → ( 𝐷 ∈ ( ( iEdg ‘ 𝐺 ) ‘ 𝑥 ) ↔ 𝐷 ∈ ( ( iEdg ‘ 𝐺 ) ‘ 𝐴 ) ) ) |
36 |
35
|
rabsnif |
⊢ { 𝑥 ∈ { 𝐴 } ∣ 𝐷 ∈ ( ( iEdg ‘ 𝐺 ) ‘ 𝑥 ) } = if ( 𝐷 ∈ ( ( iEdg ‘ 𝐺 ) ‘ 𝐴 ) , { 𝐴 } , ∅ ) |
37 |
1
|
fveq1d |
⊢ ( 𝜑 → ( ( iEdg ‘ 𝐺 ) ‘ 𝐴 ) = ( { 〈 𝐴 , 𝐸 〉 } ‘ 𝐴 ) ) |
38 |
|
fvsng |
⊢ ( ( 𝐴 ∈ 𝑋 ∧ 𝐸 ∈ 𝒫 𝑉 ) → ( { 〈 𝐴 , 𝐸 〉 } ‘ 𝐴 ) = 𝐸 ) |
39 |
3 5 38
|
syl2anc |
⊢ ( 𝜑 → ( { 〈 𝐴 , 𝐸 〉 } ‘ 𝐴 ) = 𝐸 ) |
40 |
37 39
|
eqtrd |
⊢ ( 𝜑 → ( ( iEdg ‘ 𝐺 ) ‘ 𝐴 ) = 𝐸 ) |
41 |
6 40
|
eleqtrrd |
⊢ ( 𝜑 → 𝐷 ∈ ( ( iEdg ‘ 𝐺 ) ‘ 𝐴 ) ) |
42 |
41
|
iftrued |
⊢ ( 𝜑 → if ( 𝐷 ∈ ( ( iEdg ‘ 𝐺 ) ‘ 𝐴 ) , { 𝐴 } , ∅ ) = { 𝐴 } ) |
43 |
36 42
|
syl5eq |
⊢ ( 𝜑 → { 𝑥 ∈ { 𝐴 } ∣ 𝐷 ∈ ( ( iEdg ‘ 𝐺 ) ‘ 𝑥 ) } = { 𝐴 } ) |
44 |
43
|
fveq2d |
⊢ ( 𝜑 → ( ♯ ‘ { 𝑥 ∈ { 𝐴 } ∣ 𝐷 ∈ ( ( iEdg ‘ 𝐺 ) ‘ 𝑥 ) } ) = ( ♯ ‘ { 𝐴 } ) ) |
45 |
|
hashsng |
⊢ ( 𝐴 ∈ 𝑋 → ( ♯ ‘ { 𝐴 } ) = 1 ) |
46 |
3 45
|
syl |
⊢ ( 𝜑 → ( ♯ ‘ { 𝐴 } ) = 1 ) |
47 |
44 46
|
eqtrd |
⊢ ( 𝜑 → ( ♯ ‘ { 𝑥 ∈ { 𝐴 } ∣ 𝐷 ∈ ( ( iEdg ‘ 𝐺 ) ‘ 𝑥 ) } ) = 1 ) |
48 |
47
|
adantr |
⊢ ( ( 𝜑 ∧ dom ( iEdg ‘ 𝐺 ) = { 𝐴 } ) → ( ♯ ‘ { 𝑥 ∈ { 𝐴 } ∣ 𝐷 ∈ ( ( iEdg ‘ 𝐺 ) ‘ 𝑥 ) } ) = 1 ) |
49 |
30 33 48
|
3eqtrd |
⊢ ( ( 𝜑 ∧ dom ( iEdg ‘ 𝐺 ) = { 𝐴 } ) → ( ( VtxDeg ‘ 𝐺 ) ‘ 𝐷 ) = 1 ) |
50 |
11 49
|
mpdan |
⊢ ( 𝜑 → ( ( VtxDeg ‘ 𝐺 ) ‘ 𝐷 ) = 1 ) |