Description: Define a topological division ring (which differs from a topological field only in being potentially noncommutative), which is a division ring and topological ring such that the unit group of the division ring (which is the set of nonzero elements) is a topological group. (Contributed by Mario Carneiro, 5-Oct-2015)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | df-tdrg | |- TopDRing = { r e. ( TopRing i^i DivRing ) | ( ( mulGrp ` r ) |`s ( Unit ` r ) ) e. TopGrp } |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 0 | ctdrg | |- TopDRing |
|
| 1 | vr | |- r |
|
| 2 | ctrg | |- TopRing |
|
| 3 | cdr | |- DivRing |
|
| 4 | 2 3 | cin | |- ( TopRing i^i DivRing ) |
| 5 | cmgp | |- mulGrp |
|
| 6 | 1 | cv | |- r |
| 7 | 6 5 | cfv | |- ( mulGrp ` r ) |
| 8 | cress | |- |`s |
|
| 9 | cui | |- Unit |
|
| 10 | 6 9 | cfv | |- ( Unit ` r ) |
| 11 | 7 10 8 | co | |- ( ( mulGrp ` r ) |`s ( Unit ` r ) ) |
| 12 | ctgp | |- TopGrp |
|
| 13 | 11 12 | wcel | |- ( ( mulGrp ` r ) |`s ( Unit ` r ) ) e. TopGrp |
| 14 | 13 1 4 | crab | |- { r e. ( TopRing i^i DivRing ) | ( ( mulGrp ` r ) |`s ( Unit ` r ) ) e. TopGrp } |
| 15 | 0 14 | wceq | |- TopDRing = { r e. ( TopRing i^i DivRing ) | ( ( mulGrp ` r ) |`s ( Unit ` r ) ) e. TopGrp } |