Description: The ring-span of a set of elements in a ring is the smallest subring which contains all of them. (Contributed by Stefan O'Rear, 7-Dec-2014)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | df-rgspn | |- RingSpan = ( w e. _V |-> ( s e. ~P ( Base ` w ) |-> |^| { t e. ( SubRing ` w ) | s C_ t } ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 0 | crgspn | |- RingSpan |
|
| 1 | vw | |- w |
|
| 2 | cvv | |- _V |
|
| 3 | vs | |- s |
|
| 4 | cbs | |- Base |
|
| 5 | 1 | cv | |- w |
| 6 | 5 4 | cfv | |- ( Base ` w ) |
| 7 | 6 | cpw | |- ~P ( Base ` w ) |
| 8 | vt | |- t |
|
| 9 | csubrg | |- SubRing |
|
| 10 | 5 9 | cfv | |- ( SubRing ` w ) |
| 11 | 3 | cv | |- s |
| 12 | 8 | cv | |- t |
| 13 | 11 12 | wss | |- s C_ t |
| 14 | 13 8 10 | crab | |- { t e. ( SubRing ` w ) | s C_ t } |
| 15 | 14 | cint | |- |^| { t e. ( SubRing ` w ) | s C_ t } |
| 16 | 3 7 15 | cmpt | |- ( s e. ~P ( Base ` w ) |-> |^| { t e. ( SubRing ` w ) | s C_ t } ) |
| 17 | 1 2 16 | cmpt | |- ( w e. _V |-> ( s e. ~P ( Base ` w ) |-> |^| { t e. ( SubRing ` w ) | s C_ t } ) ) |
| 18 | 0 17 | wceq | |- RingSpan = ( w e. _V |-> ( s e. ~P ( Base ` w ) |-> |^| { t e. ( SubRing ` w ) | s C_ t } ) ) |