Metamath Proof Explorer


Theorem subgrprop3

Description: The properties of a subgraph: If S is a subgraph of G , its vertices are also vertices of G , and its edges are also edges of G . (Contributed by AV, 19-Nov-2020)

Ref Expression
Hypotheses subgrprop3.v 𝑉 = ( Vtx ‘ 𝑆 )
subgrprop3.a 𝐴 = ( Vtx ‘ 𝐺 )
subgrprop3.e 𝐸 = ( Edg ‘ 𝑆 )
subgrprop3.b 𝐵 = ( Edg ‘ 𝐺 )
Assertion subgrprop3 ( 𝑆 SubGraph 𝐺 → ( 𝑉𝐴𝐸𝐵 ) )

Proof

Step Hyp Ref Expression
1 subgrprop3.v 𝑉 = ( Vtx ‘ 𝑆 )
2 subgrprop3.a 𝐴 = ( Vtx ‘ 𝐺 )
3 subgrprop3.e 𝐸 = ( Edg ‘ 𝑆 )
4 subgrprop3.b 𝐵 = ( Edg ‘ 𝐺 )
5 eqid ( iEdg ‘ 𝑆 ) = ( iEdg ‘ 𝑆 )
6 eqid ( iEdg ‘ 𝐺 ) = ( iEdg ‘ 𝐺 )
7 1 2 5 6 3 subgrprop2 ( 𝑆 SubGraph 𝐺 → ( 𝑉𝐴 ∧ ( iEdg ‘ 𝑆 ) ⊆ ( iEdg ‘ 𝐺 ) ∧ 𝐸 ⊆ 𝒫 𝑉 ) )
8 3simpa ( ( 𝑉𝐴 ∧ ( iEdg ‘ 𝑆 ) ⊆ ( iEdg ‘ 𝐺 ) ∧ 𝐸 ⊆ 𝒫 𝑉 ) → ( 𝑉𝐴 ∧ ( iEdg ‘ 𝑆 ) ⊆ ( iEdg ‘ 𝐺 ) ) )
9 7 8 syl ( 𝑆 SubGraph 𝐺 → ( 𝑉𝐴 ∧ ( iEdg ‘ 𝑆 ) ⊆ ( iEdg ‘ 𝐺 ) ) )
10 simprl ( ( 𝑆 SubGraph 𝐺 ∧ ( 𝑉𝐴 ∧ ( iEdg ‘ 𝑆 ) ⊆ ( iEdg ‘ 𝐺 ) ) ) → 𝑉𝐴 )
11 rnss ( ( iEdg ‘ 𝑆 ) ⊆ ( iEdg ‘ 𝐺 ) → ran ( iEdg ‘ 𝑆 ) ⊆ ran ( iEdg ‘ 𝐺 ) )
12 11 ad2antll ( ( 𝑆 SubGraph 𝐺 ∧ ( 𝑉𝐴 ∧ ( iEdg ‘ 𝑆 ) ⊆ ( iEdg ‘ 𝐺 ) ) ) → ran ( iEdg ‘ 𝑆 ) ⊆ ran ( iEdg ‘ 𝐺 ) )
13 subgrv ( 𝑆 SubGraph 𝐺 → ( 𝑆 ∈ V ∧ 𝐺 ∈ V ) )
14 edgval ( Edg ‘ 𝑆 ) = ran ( iEdg ‘ 𝑆 )
15 14 a1i ( ( 𝑆 ∈ V ∧ 𝐺 ∈ V ) → ( Edg ‘ 𝑆 ) = ran ( iEdg ‘ 𝑆 ) )
16 3 15 syl5eq ( ( 𝑆 ∈ V ∧ 𝐺 ∈ V ) → 𝐸 = ran ( iEdg ‘ 𝑆 ) )
17 edgval ( Edg ‘ 𝐺 ) = ran ( iEdg ‘ 𝐺 )
18 17 a1i ( ( 𝑆 ∈ V ∧ 𝐺 ∈ V ) → ( Edg ‘ 𝐺 ) = ran ( iEdg ‘ 𝐺 ) )
19 4 18 syl5eq ( ( 𝑆 ∈ V ∧ 𝐺 ∈ V ) → 𝐵 = ran ( iEdg ‘ 𝐺 ) )
20 16 19 sseq12d ( ( 𝑆 ∈ V ∧ 𝐺 ∈ V ) → ( 𝐸𝐵 ↔ ran ( iEdg ‘ 𝑆 ) ⊆ ran ( iEdg ‘ 𝐺 ) ) )
21 13 20 syl ( 𝑆 SubGraph 𝐺 → ( 𝐸𝐵 ↔ ran ( iEdg ‘ 𝑆 ) ⊆ ran ( iEdg ‘ 𝐺 ) ) )
22 21 adantr ( ( 𝑆 SubGraph 𝐺 ∧ ( 𝑉𝐴 ∧ ( iEdg ‘ 𝑆 ) ⊆ ( iEdg ‘ 𝐺 ) ) ) → ( 𝐸𝐵 ↔ ran ( iEdg ‘ 𝑆 ) ⊆ ran ( iEdg ‘ 𝐺 ) ) )
23 12 22 mpbird ( ( 𝑆 SubGraph 𝐺 ∧ ( 𝑉𝐴 ∧ ( iEdg ‘ 𝑆 ) ⊆ ( iEdg ‘ 𝐺 ) ) ) → 𝐸𝐵 )
24 10 23 jca ( ( 𝑆 SubGraph 𝐺 ∧ ( 𝑉𝐴 ∧ ( iEdg ‘ 𝑆 ) ⊆ ( iEdg ‘ 𝐺 ) ) ) → ( 𝑉𝐴𝐸𝐵 ) )
25 9 24 mpdan ( 𝑆 SubGraph 𝐺 → ( 𝑉𝐴𝐸𝐵 ) )