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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 | |- ( ph -> G e. USHGraph ) |
|
| ushgrun.h | |- ( ph -> H e. USHGraph ) |
||
| ushgrun.e | |- E = ( iEdg ` G ) |
||
| ushgrun.f | |- F = ( iEdg ` H ) |
||
| ushgrun.vg | |- V = ( Vtx ` G ) |
||
| ushgrun.vh | |- ( ph -> ( Vtx ` H ) = V ) |
||
| ushgrun.i | |- ( ph -> ( dom E i^i dom F ) = (/) ) |
||
| Assertion | ushgrunop | |- ( ph -> <. V , ( E u. F ) >. e. UHGraph ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | ushgrun.g | |- ( ph -> G e. USHGraph ) |
|
| 2 | ushgrun.h | |- ( ph -> H e. USHGraph ) |
|
| 3 | ushgrun.e | |- E = ( iEdg ` G ) |
|
| 4 | ushgrun.f | |- F = ( iEdg ` H ) |
|
| 5 | ushgrun.vg | |- V = ( Vtx ` G ) |
|
| 6 | ushgrun.vh | |- ( ph -> ( Vtx ` H ) = V ) |
|
| 7 | ushgrun.i | |- ( ph -> ( dom E i^i dom F ) = (/) ) |
|
| 8 | ushgruhgr | |- ( G e. USHGraph -> G e. UHGraph ) |
|
| 9 | 1 8 | syl | |- ( ph -> G e. UHGraph ) |
| 10 | ushgruhgr | |- ( H e. USHGraph -> H e. UHGraph ) |
|
| 11 | 2 10 | syl | |- ( ph -> H e. UHGraph ) |
| 12 | 9 11 3 4 5 6 7 | uhgrunop | |- ( ph -> <. V , ( E u. F ) >. e. UHGraph ) |