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Description: The class of all simple graphs is a superclass of the class of empty graphs represented as ordered pairs. (Contributed by AV, 27-Dec-2020)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | griedg0prc.u | |- U = { <. v , e >. | e : (/) --> (/) } |
|
| Assertion | griedg0ssusgr | |- U C_ USGraph |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | griedg0prc.u | |- U = { <. v , e >. | e : (/) --> (/) } |
|
| 2 | 1 | eleq2i | |- ( g e. U <-> g e. { <. v , e >. | e : (/) --> (/) } ) |
| 3 | elopab | |- ( g e. { <. v , e >. | e : (/) --> (/) } <-> E. v E. e ( g = <. v , e >. /\ e : (/) --> (/) ) ) |
|
| 4 | 2 3 | bitri | |- ( g e. U <-> E. v E. e ( g = <. v , e >. /\ e : (/) --> (/) ) ) |
| 5 | opex | |- <. v , e >. e. _V |
|
| 6 | 5 | a1i | |- ( e : (/) --> (/) -> <. v , e >. e. _V ) |
| 7 | vex | |- v e. _V |
|
| 8 | vex | |- e e. _V |
|
| 9 | 7 8 | opiedgfvi | |- ( iEdg ` <. v , e >. ) = e |
| 10 | f0bi | |- ( e : (/) --> (/) <-> e = (/) ) |
|
| 11 | 10 | biimpi | |- ( e : (/) --> (/) -> e = (/) ) |
| 12 | 9 11 | eqtrid | |- ( e : (/) --> (/) -> ( iEdg ` <. v , e >. ) = (/) ) |
| 13 | 6 12 | usgr0e | |- ( e : (/) --> (/) -> <. v , e >. e. USGraph ) |
| 14 | 13 | adantl | |- ( ( g = <. v , e >. /\ e : (/) --> (/) ) -> <. v , e >. e. USGraph ) |
| 15 | eleq1 | |- ( g = <. v , e >. -> ( g e. USGraph <-> <. v , e >. e. USGraph ) ) |
|
| 16 | 15 | adantr | |- ( ( g = <. v , e >. /\ e : (/) --> (/) ) -> ( g e. USGraph <-> <. v , e >. e. USGraph ) ) |
| 17 | 14 16 | mpbird | |- ( ( g = <. v , e >. /\ e : (/) --> (/) ) -> g e. USGraph ) |
| 18 | 17 | exlimivv | |- ( E. v E. e ( g = <. v , e >. /\ e : (/) --> (/) ) -> g e. USGraph ) |
| 19 | 4 18 | sylbi | |- ( g e. U -> g e. USGraph ) |
| 20 | 19 | ssriv | |- U C_ USGraph |