Description: Every ring contains a zero ideal. (Contributed by Stefan O'Rear, 3-Jan-2015) (Proof shortened by AV, 18-Apr-2025)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | rnglidl0.u | |- U = ( LIdeal ` R ) | |
| rnglidl0.z | |- .0. = ( 0g ` R ) | ||
| Assertion | lidl0 | |- ( R e. Ring -> { .0. } e. U ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | rnglidl0.u | |- U = ( LIdeal ` R ) | |
| 2 | rnglidl0.z | |- .0. = ( 0g ` R ) | |
| 3 | ringrng | |- ( R e. Ring -> R e. Rng ) | |
| 4 | 1 2 | rnglidl0 |  |-  ( R e. Rng -> { .0. } e. U ) | 
| 5 | 3 4 | syl |  |-  ( R e. Ring -> { .0. } e. U ) |