Description: Closed walks (represented by words) are words. (Contributed by Alexander van der Vekens, 25-Mar-2018) (Revised by AV, 25-Apr-2021)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | clwwlksswrd | |- ( ClWWalks ` G ) C_ Word ( Vtx ` G ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | eqid | |- ( Vtx ` G ) = ( Vtx ` G ) |
|
| 2 | eqid | |- ( Edg ` G ) = ( Edg ` G ) |
|
| 3 | 1 2 | clwwlk | |- ( ClWWalks ` G ) = { w e. Word ( Vtx ` G ) | ( w =/= (/) /\ A. i e. ( 0 ..^ ( ( # ` w ) - 1 ) ) { ( w ` i ) , ( w ` ( i + 1 ) ) } e. ( Edg ` G ) /\ { ( lastS ` w ) , ( w ` 0 ) } e. ( Edg ` G ) ) } |
| 4 | 3 | ssrab3 | |- ( ClWWalks ` G ) C_ Word ( Vtx ` G ) |