Description: Every ring contains a zero right ideal. (Contributed by AV, 13-Feb-2025)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | ridl0.u | |- U = ( LIdeal ` ( oppR ` R ) )  | 
					|
| ridl0.z | |- .0. = ( 0g ` R )  | 
					||
| Assertion | ridl0 | |- ( R e. Ring -> { .0. } e. U ) | 
				
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | ridl0.u | |- U = ( LIdeal ` ( oppR ` R ) )  | 
						|
| 2 | ridl0.z | |- .0. = ( 0g ` R )  | 
						|
| 3 | eqid | |- ( oppR ` R ) = ( oppR ` R )  | 
						|
| 4 | 3 | opprring | |- ( R e. Ring -> ( oppR ` R ) e. Ring )  | 
						
| 5 | 3 2 | oppr0 | |- .0. = ( 0g ` ( oppR ` R ) )  | 
						
| 6 | 1 5 | lidl0 |  |-  ( ( oppR ` R ) e. Ring -> { .0. } e. U ) | 
						
| 7 | 4 6 | syl |  |-  ( R e. Ring -> { .0. } e. U ) |