Description: The base set of a zero ring, a ring which is not a nonzero ring, is the singleton of the zero element. (Contributed by AV, 17-Apr-2020)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | 0ring.b | |- B = ( Base ` R ) | |
| 0ring.0 | |- .0. = ( 0g ` R ) | ||
| Assertion | 0ringbas | |- ( R e. ( Ring \ NzRing ) -> B = { .0. } ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | 0ring.b | |- B = ( Base ` R ) | |
| 2 | 0ring.0 | |- .0. = ( 0g ` R ) | |
| 3 | 1 2 | 0ringdif |  |-  ( R e. ( Ring \ NzRing ) <-> ( R e. Ring /\ B = { .0. } ) ) | 
| 4 | 3 | simprbi |  |-  ( R e. ( Ring \ NzRing ) -> B = { .0. } ) |