Description: In a unitary ring, the ring unity is not a zero divisor. (Contributed by AV, 7-Mar-2025)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | ringunitnzdiv.b | |- B = ( Base ` R ) | |
| ringunitnzdiv.z | |- .0. = ( 0g ` R ) | ||
| ringunitnzdiv.t | |- .x. = ( .r ` R ) | ||
| ringunitnzdiv.r | |- ( ph -> R e. Ring ) | ||
| ringunitnzdiv.y | |- ( ph -> Y e. B ) | ||
| ring1nzdiv.x | |- .1. = ( 1r ` R ) | ||
| Assertion | ring1nzdiv | |- ( ph -> ( ( .1. .x. Y ) = .0. <-> Y = .0. ) ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | ringunitnzdiv.b | |- B = ( Base ` R ) | |
| 2 | ringunitnzdiv.z | |- .0. = ( 0g ` R ) | |
| 3 | ringunitnzdiv.t | |- .x. = ( .r ` R ) | |
| 4 | ringunitnzdiv.r | |- ( ph -> R e. Ring ) | |
| 5 | ringunitnzdiv.y | |- ( ph -> Y e. B ) | |
| 6 | ring1nzdiv.x | |- .1. = ( 1r ` R ) | |
| 7 | eqid | |- ( Unit ` R ) = ( Unit ` R ) | |
| 8 | 7 6 | 1unit | |- ( R e. Ring -> .1. e. ( Unit ` R ) ) | 
| 9 | 4 8 | syl | |- ( ph -> .1. e. ( Unit ` R ) ) | 
| 10 | 1 2 3 4 5 9 | ringunitnzdiv | |- ( ph -> ( ( .1. .x. Y ) = .0. <-> Y = .0. ) ) |