Metamath Proof Explorer


Theorem ushgrunop

Description: The union of two (undirected) simple hypergraphs (with the same vertex set) represented as ordered pair: If <. V , E >. and <. V , F >. are simple hypergraphs, then <. V , E u. F >. is a (not necessarily simple) hypergraph - the vertex set stays the same, but the edges from both graphs are kept, possibly resulting in two edges between two vertices. (Contributed by AV, 29-Nov-2020) (Revised by AV, 24-Oct-2021)

Ref Expression
Hypotheses ushgrun.g ⊢ φ → G ∈ USHGraph
ushgrun.h ⊢ φ → H ∈ USHGraph
ushgrun.e ⊢ E = iEdg ⁡ G
ushgrun.f ⊢ F = iEdg ⁡ H
ushgrun.vg ⊢ V = Vtx ⁡ G
ushgrun.vh ⊢ φ → Vtx ⁡ H = V
ushgrun.i ⊢ φ → dom ⁡ E ∩ dom ⁡ F = ∅
Assertion ushgrunop ⊢ φ → V E ∪ F ∈ UHGraph

Proof

Step Hyp Ref Expression
1 ushgrun.g ⊢ φ → G ∈ USHGraph
2 ushgrun.h ⊢ φ → H ∈ USHGraph
3 ushgrun.e ⊢ E = iEdg ⁡ G
4 ushgrun.f ⊢ F = iEdg ⁡ H
5 ushgrun.vg ⊢ V = Vtx ⁡ G
6 ushgrun.vh ⊢ φ → Vtx ⁡ H = V
7 ushgrun.i ⊢ φ → dom ⁡ E ∩ dom ⁡ F = ∅
8 ushgruhgr ⊢ G ∈ USHGraph → G ∈ UHGraph
9 1 8 syl ⊢ φ → G ∈ UHGraph
10 ushgruhgr ⊢ H ∈ USHGraph → H ∈ UHGraph
11 2 10 syl ⊢ φ → H ∈ UHGraph
12 9 11 3 4 5 6 7 uhgrunop ⊢ φ → V E ∪ F ∈ UHGraph