Metamath Proof Explorer


Theorem umgrreslem

Description: Lemma for umgrres and usgrres . (Contributed by AV, 27-Nov-2020) (Revised by AV, 19-Dec-2021)

Ref Expression
Hypotheses upgrres.v 𝑉 = ( Vtx ‘ 𝐺 )
upgrres.e 𝐸 = ( iEdg ‘ 𝐺 )
upgrres.f 𝐹 = { 𝑖 ∈ dom 𝐸𝑁 ∉ ( 𝐸𝑖 ) }
Assertion umgrreslem ( ( 𝐺 ∈ UMGraph ∧ 𝑁𝑉 ) → ran ( 𝐸𝐹 ) ⊆ { 𝑝 ∈ 𝒫 ( 𝑉 ∖ { 𝑁 } ) ∣ ( ♯ ‘ 𝑝 ) = 2 } )

Proof

Step Hyp Ref Expression
1 upgrres.v 𝑉 = ( Vtx ‘ 𝐺 )
2 upgrres.e 𝐸 = ( iEdg ‘ 𝐺 )
3 upgrres.f 𝐹 = { 𝑖 ∈ dom 𝐸𝑁 ∉ ( 𝐸𝑖 ) }
4 df-ima ( 𝐸𝐹 ) = ran ( 𝐸𝐹 )
5 fveq2 ( 𝑖 = 𝑗 → ( 𝐸𝑖 ) = ( 𝐸𝑗 ) )
6 neleq2 ( ( 𝐸𝑖 ) = ( 𝐸𝑗 ) → ( 𝑁 ∉ ( 𝐸𝑖 ) ↔ 𝑁 ∉ ( 𝐸𝑗 ) ) )
7 5 6 syl ( 𝑖 = 𝑗 → ( 𝑁 ∉ ( 𝐸𝑖 ) ↔ 𝑁 ∉ ( 𝐸𝑗 ) ) )
8 7 3 elrab2 ( 𝑗𝐹 ↔ ( 𝑗 ∈ dom 𝐸𝑁 ∉ ( 𝐸𝑗 ) ) )
9 1 2 umgrf ( 𝐺 ∈ UMGraph → 𝐸 : dom 𝐸 ⟶ { 𝑝 ∈ 𝒫 𝑉 ∣ ( ♯ ‘ 𝑝 ) = 2 } )
10 ffvelrn ( ( 𝐸 : dom 𝐸 ⟶ { 𝑝 ∈ 𝒫 𝑉 ∣ ( ♯ ‘ 𝑝 ) = 2 } ∧ 𝑗 ∈ dom 𝐸 ) → ( 𝐸𝑗 ) ∈ { 𝑝 ∈ 𝒫 𝑉 ∣ ( ♯ ‘ 𝑝 ) = 2 } )
11 fveqeq2 ( 𝑝 = ( 𝐸𝑗 ) → ( ( ♯ ‘ 𝑝 ) = 2 ↔ ( ♯ ‘ ( 𝐸𝑗 ) ) = 2 ) )
12 11 elrab ( ( 𝐸𝑗 ) ∈ { 𝑝 ∈ 𝒫 𝑉 ∣ ( ♯ ‘ 𝑝 ) = 2 } ↔ ( ( 𝐸𝑗 ) ∈ 𝒫 𝑉 ∧ ( ♯ ‘ ( 𝐸𝑗 ) ) = 2 ) )
13 simpll ( ( ( ( 𝐸𝑗 ) ∈ 𝒫 𝑉 ∧ ( ♯ ‘ ( 𝐸𝑗 ) ) = 2 ) ∧ 𝑁 ∉ ( 𝐸𝑗 ) ) → ( 𝐸𝑗 ) ∈ 𝒫 𝑉 )
14 elpwi ( ( 𝐸𝑗 ) ∈ 𝒫 𝑉 → ( 𝐸𝑗 ) ⊆ 𝑉 )
15 14 adantr ( ( ( 𝐸𝑗 ) ∈ 𝒫 𝑉 ∧ ( ♯ ‘ ( 𝐸𝑗 ) ) = 2 ) → ( 𝐸𝑗 ) ⊆ 𝑉 )
16 15 adantr ( ( ( ( 𝐸𝑗 ) ∈ 𝒫 𝑉 ∧ ( ♯ ‘ ( 𝐸𝑗 ) ) = 2 ) ∧ 𝑁 ∉ ( 𝐸𝑗 ) ) → ( 𝐸𝑗 ) ⊆ 𝑉 )
17 simpr ( ( ( ( 𝐸𝑗 ) ∈ 𝒫 𝑉 ∧ ( ♯ ‘ ( 𝐸𝑗 ) ) = 2 ) ∧ 𝑁 ∉ ( 𝐸𝑗 ) ) → 𝑁 ∉ ( 𝐸𝑗 ) )
18 elpwdifsn ( ( ( 𝐸𝑗 ) ∈ 𝒫 𝑉 ∧ ( 𝐸𝑗 ) ⊆ 𝑉𝑁 ∉ ( 𝐸𝑗 ) ) → ( 𝐸𝑗 ) ∈ 𝒫 ( 𝑉 ∖ { 𝑁 } ) )
19 13 16 17 18 syl3anc ( ( ( ( 𝐸𝑗 ) ∈ 𝒫 𝑉 ∧ ( ♯ ‘ ( 𝐸𝑗 ) ) = 2 ) ∧ 𝑁 ∉ ( 𝐸𝑗 ) ) → ( 𝐸𝑗 ) ∈ 𝒫 ( 𝑉 ∖ { 𝑁 } ) )
20 simpr ( ( ( 𝐸𝑗 ) ∈ 𝒫 𝑉 ∧ ( ♯ ‘ ( 𝐸𝑗 ) ) = 2 ) → ( ♯ ‘ ( 𝐸𝑗 ) ) = 2 )
21 20 adantr ( ( ( ( 𝐸𝑗 ) ∈ 𝒫 𝑉 ∧ ( ♯ ‘ ( 𝐸𝑗 ) ) = 2 ) ∧ 𝑁 ∉ ( 𝐸𝑗 ) ) → ( ♯ ‘ ( 𝐸𝑗 ) ) = 2 )
22 11 19 21 elrabd ( ( ( ( 𝐸𝑗 ) ∈ 𝒫 𝑉 ∧ ( ♯ ‘ ( 𝐸𝑗 ) ) = 2 ) ∧ 𝑁 ∉ ( 𝐸𝑗 ) ) → ( 𝐸𝑗 ) ∈ { 𝑝 ∈ 𝒫 ( 𝑉 ∖ { 𝑁 } ) ∣ ( ♯ ‘ 𝑝 ) = 2 } )
23 22 ex ( ( ( 𝐸𝑗 ) ∈ 𝒫 𝑉 ∧ ( ♯ ‘ ( 𝐸𝑗 ) ) = 2 ) → ( 𝑁 ∉ ( 𝐸𝑗 ) → ( 𝐸𝑗 ) ∈ { 𝑝 ∈ 𝒫 ( 𝑉 ∖ { 𝑁 } ) ∣ ( ♯ ‘ 𝑝 ) = 2 } ) )
24 23 a1d ( ( ( 𝐸𝑗 ) ∈ 𝒫 𝑉 ∧ ( ♯ ‘ ( 𝐸𝑗 ) ) = 2 ) → ( 𝑁𝑉 → ( 𝑁 ∉ ( 𝐸𝑗 ) → ( 𝐸𝑗 ) ∈ { 𝑝 ∈ 𝒫 ( 𝑉 ∖ { 𝑁 } ) ∣ ( ♯ ‘ 𝑝 ) = 2 } ) ) )
25 12 24 sylbi ( ( 𝐸𝑗 ) ∈ { 𝑝 ∈ 𝒫 𝑉 ∣ ( ♯ ‘ 𝑝 ) = 2 } → ( 𝑁𝑉 → ( 𝑁 ∉ ( 𝐸𝑗 ) → ( 𝐸𝑗 ) ∈ { 𝑝 ∈ 𝒫 ( 𝑉 ∖ { 𝑁 } ) ∣ ( ♯ ‘ 𝑝 ) = 2 } ) ) )
26 10 25 syl ( ( 𝐸 : dom 𝐸 ⟶ { 𝑝 ∈ 𝒫 𝑉 ∣ ( ♯ ‘ 𝑝 ) = 2 } ∧ 𝑗 ∈ dom 𝐸 ) → ( 𝑁𝑉 → ( 𝑁 ∉ ( 𝐸𝑗 ) → ( 𝐸𝑗 ) ∈ { 𝑝 ∈ 𝒫 ( 𝑉 ∖ { 𝑁 } ) ∣ ( ♯ ‘ 𝑝 ) = 2 } ) ) )
27 26 ex ( 𝐸 : dom 𝐸 ⟶ { 𝑝 ∈ 𝒫 𝑉 ∣ ( ♯ ‘ 𝑝 ) = 2 } → ( 𝑗 ∈ dom 𝐸 → ( 𝑁𝑉 → ( 𝑁 ∉ ( 𝐸𝑗 ) → ( 𝐸𝑗 ) ∈ { 𝑝 ∈ 𝒫 ( 𝑉 ∖ { 𝑁 } ) ∣ ( ♯ ‘ 𝑝 ) = 2 } ) ) ) )
28 27 com23 ( 𝐸 : dom 𝐸 ⟶ { 𝑝 ∈ 𝒫 𝑉 ∣ ( ♯ ‘ 𝑝 ) = 2 } → ( 𝑁𝑉 → ( 𝑗 ∈ dom 𝐸 → ( 𝑁 ∉ ( 𝐸𝑗 ) → ( 𝐸𝑗 ) ∈ { 𝑝 ∈ 𝒫 ( 𝑉 ∖ { 𝑁 } ) ∣ ( ♯ ‘ 𝑝 ) = 2 } ) ) ) )
29 9 28 syl ( 𝐺 ∈ UMGraph → ( 𝑁𝑉 → ( 𝑗 ∈ dom 𝐸 → ( 𝑁 ∉ ( 𝐸𝑗 ) → ( 𝐸𝑗 ) ∈ { 𝑝 ∈ 𝒫 ( 𝑉 ∖ { 𝑁 } ) ∣ ( ♯ ‘ 𝑝 ) = 2 } ) ) ) )
30 29 imp4b ( ( 𝐺 ∈ UMGraph ∧ 𝑁𝑉 ) → ( ( 𝑗 ∈ dom 𝐸𝑁 ∉ ( 𝐸𝑗 ) ) → ( 𝐸𝑗 ) ∈ { 𝑝 ∈ 𝒫 ( 𝑉 ∖ { 𝑁 } ) ∣ ( ♯ ‘ 𝑝 ) = 2 } ) )
31 8 30 syl5bi ( ( 𝐺 ∈ UMGraph ∧ 𝑁𝑉 ) → ( 𝑗𝐹 → ( 𝐸𝑗 ) ∈ { 𝑝 ∈ 𝒫 ( 𝑉 ∖ { 𝑁 } ) ∣ ( ♯ ‘ 𝑝 ) = 2 } ) )
32 31 ralrimiv ( ( 𝐺 ∈ UMGraph ∧ 𝑁𝑉 ) → ∀ 𝑗𝐹 ( 𝐸𝑗 ) ∈ { 𝑝 ∈ 𝒫 ( 𝑉 ∖ { 𝑁 } ) ∣ ( ♯ ‘ 𝑝 ) = 2 } )
33 umgruhgr ( 𝐺 ∈ UMGraph → 𝐺 ∈ UHGraph )
34 2 uhgrfun ( 𝐺 ∈ UHGraph → Fun 𝐸 )
35 33 34 syl ( 𝐺 ∈ UMGraph → Fun 𝐸 )
36 35 adantr ( ( 𝐺 ∈ UMGraph ∧ 𝑁𝑉 ) → Fun 𝐸 )
37 3 ssrab3 𝐹 ⊆ dom 𝐸
38 funimass4 ( ( Fun 𝐸𝐹 ⊆ dom 𝐸 ) → ( ( 𝐸𝐹 ) ⊆ { 𝑝 ∈ 𝒫 ( 𝑉 ∖ { 𝑁 } ) ∣ ( ♯ ‘ 𝑝 ) = 2 } ↔ ∀ 𝑗𝐹 ( 𝐸𝑗 ) ∈ { 𝑝 ∈ 𝒫 ( 𝑉 ∖ { 𝑁 } ) ∣ ( ♯ ‘ 𝑝 ) = 2 } ) )
39 36 37 38 sylancl ( ( 𝐺 ∈ UMGraph ∧ 𝑁𝑉 ) → ( ( 𝐸𝐹 ) ⊆ { 𝑝 ∈ 𝒫 ( 𝑉 ∖ { 𝑁 } ) ∣ ( ♯ ‘ 𝑝 ) = 2 } ↔ ∀ 𝑗𝐹 ( 𝐸𝑗 ) ∈ { 𝑝 ∈ 𝒫 ( 𝑉 ∖ { 𝑁 } ) ∣ ( ♯ ‘ 𝑝 ) = 2 } ) )
40 32 39 mpbird ( ( 𝐺 ∈ UMGraph ∧ 𝑁𝑉 ) → ( 𝐸𝐹 ) ⊆ { 𝑝 ∈ 𝒫 ( 𝑉 ∖ { 𝑁 } ) ∣ ( ♯ ‘ 𝑝 ) = 2 } )
41 4 40 eqsstrrid ( ( 𝐺 ∈ UMGraph ∧ 𝑁𝑉 ) → ran ( 𝐸𝐹 ) ⊆ { 𝑝 ∈ 𝒫 ( 𝑉 ∖ { 𝑁 } ) ∣ ( ♯ ‘ 𝑝 ) = 2 } )