Theorem umgr2adedgwlklem

Description: Lemma for umgr2adedgwlk , umgr2adedgspth , etc. (Contributed by Alexander van der Vekens, 1-Feb-2018) (Revised by AV, 29-Jan-2021)

	Ref	Expression
Hypothesis	umgr2adedgwlk.e	⊢ 𝐸 = ( Edg ‘ 𝐺 )
Assertion	umgr2adedgwlklem	⊢ ( ( 𝐺 ∈ UMGraph ∧ { 𝐴 , 𝐵 } ∈ 𝐸 ∧ { 𝐵 , 𝐶 } ∈ 𝐸 ) → ( ( 𝐴 ≠ 𝐵 ∧ 𝐵 ≠ 𝐶 ) ∧ ( 𝐴 ∈ ( Vtx ‘ 𝐺 ) ∧ 𝐵 ∈ ( Vtx ‘ 𝐺 ) ∧ 𝐶 ∈ ( Vtx ‘ 𝐺 ) ) ) )

Proof

Step	Hyp	Ref	Expression
1		umgr2adedgwlk.e	⊢ 𝐸 = ( Edg ‘ 𝐺 )
2	1	umgredgne	⊢ ( ( 𝐺 ∈ UMGraph ∧ { 𝐴 , 𝐵 } ∈ 𝐸 ) → 𝐴 ≠ 𝐵 )
3	2	ex	⊢ ( 𝐺 ∈ UMGraph → ( { 𝐴 , 𝐵 } ∈ 𝐸 → 𝐴 ≠ 𝐵 ) )
4	1	umgredgne	⊢ ( ( 𝐺 ∈ UMGraph ∧ { 𝐵 , 𝐶 } ∈ 𝐸 ) → 𝐵 ≠ 𝐶 )
5	4	ex	⊢ ( 𝐺 ∈ UMGraph → ( { 𝐵 , 𝐶 } ∈ 𝐸 → 𝐵 ≠ 𝐶 ) )
6	3 5	anim12d	⊢ ( 𝐺 ∈ UMGraph → ( ( { 𝐴 , 𝐵 } ∈ 𝐸 ∧ { 𝐵 , 𝐶 } ∈ 𝐸 ) → ( 𝐴 ≠ 𝐵 ∧ 𝐵 ≠ 𝐶 ) ) )
7	6	3impib	⊢ ( ( 𝐺 ∈ UMGraph ∧ { 𝐴 , 𝐵 } ∈ 𝐸 ∧ { 𝐵 , 𝐶 } ∈ 𝐸 ) → ( 𝐴 ≠ 𝐵 ∧ 𝐵 ≠ 𝐶 ) )
8		eqid	⊢ ( Vtx ‘ 𝐺 ) = ( Vtx ‘ 𝐺 )
9	8 1	umgrpredgv	⊢ ( ( 𝐺 ∈ UMGraph ∧ { 𝐴 , 𝐵 } ∈ 𝐸 ) → ( 𝐴 ∈ ( Vtx ‘ 𝐺 ) ∧ 𝐵 ∈ ( Vtx ‘ 𝐺 ) ) )
10	9	simpld	⊢ ( ( 𝐺 ∈ UMGraph ∧ { 𝐴 , 𝐵 } ∈ 𝐸 ) → 𝐴 ∈ ( Vtx ‘ 𝐺 ) )
11	10	3adant3	⊢ ( ( 𝐺 ∈ UMGraph ∧ { 𝐴 , 𝐵 } ∈ 𝐸 ∧ { 𝐵 , 𝐶 } ∈ 𝐸 ) → 𝐴 ∈ ( Vtx ‘ 𝐺 ) )
12	8 1	umgrpredgv	⊢ ( ( 𝐺 ∈ UMGraph ∧ { 𝐵 , 𝐶 } ∈ 𝐸 ) → ( 𝐵 ∈ ( Vtx ‘ 𝐺 ) ∧ 𝐶 ∈ ( Vtx ‘ 𝐺 ) ) )
13	12	simpld	⊢ ( ( 𝐺 ∈ UMGraph ∧ { 𝐵 , 𝐶 } ∈ 𝐸 ) → 𝐵 ∈ ( Vtx ‘ 𝐺 ) )
14	13	3adant2	⊢ ( ( 𝐺 ∈ UMGraph ∧ { 𝐴 , 𝐵 } ∈ 𝐸 ∧ { 𝐵 , 𝐶 } ∈ 𝐸 ) → 𝐵 ∈ ( Vtx ‘ 𝐺 ) )
15	12	simprd	⊢ ( ( 𝐺 ∈ UMGraph ∧ { 𝐵 , 𝐶 } ∈ 𝐸 ) → 𝐶 ∈ ( Vtx ‘ 𝐺 ) )
16	15	3adant2	⊢ ( ( 𝐺 ∈ UMGraph ∧ { 𝐴 , 𝐵 } ∈ 𝐸 ∧ { 𝐵 , 𝐶 } ∈ 𝐸 ) → 𝐶 ∈ ( Vtx ‘ 𝐺 ) )
17	11 14 16	3jca	⊢ ( ( 𝐺 ∈ UMGraph ∧ { 𝐴 , 𝐵 } ∈ 𝐸 ∧ { 𝐵 , 𝐶 } ∈ 𝐸 ) → ( 𝐴 ∈ ( Vtx ‘ 𝐺 ) ∧ 𝐵 ∈ ( Vtx ‘ 𝐺 ) ∧ 𝐶 ∈ ( Vtx ‘ 𝐺 ) ) )
18	7 17	jca	⊢ ( ( 𝐺 ∈ UMGraph ∧ { 𝐴 , 𝐵 } ∈ 𝐸 ∧ { 𝐵 , 𝐶 } ∈ 𝐸 ) → ( ( 𝐴 ≠ 𝐵 ∧ 𝐵 ≠ 𝐶 ) ∧ ( 𝐴 ∈ ( Vtx ‘ 𝐺 ) ∧ 𝐵 ∈ ( Vtx ‘ 𝐺 ) ∧ 𝐶 ∈ ( Vtx ‘ 𝐺 ) ) ) )