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 | ||
| rnglidl0.z | |||
| Assertion | lidl0 | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | rnglidl0.u | ||
| 2 | rnglidl0.z | ||
| 3 | ringrng | ||
| 4 | 1 2 | rnglidl0 | |
| 5 | 3 4 | syl |