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Description: In a domain, factors of a nonzero product are nonzero. (Contributed by Thierry Arnoux, 8-Jun-2025)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | domnmuln0rd.b | |- B = ( Base ` R ) |
|
| domnmuln0rd.t | |- .x. = ( .r ` R ) |
||
| domnmuln0rd.z | |- .0. = ( 0g ` R ) |
||
| domnmuln0rd.1 | |- ( ph -> R e. Domn ) |
||
| domnmuln0rd.2 | |- ( ph -> X e. B ) |
||
| domnmuln0rd.3 | |- ( ph -> Y e. B ) |
||
| domnmuln0rd.4 | |- ( ph -> ( X .x. Y ) =/= .0. ) |
||
| Assertion | domnmuln0rd | |- ( ph -> ( X =/= .0. /\ Y =/= .0. ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | domnmuln0rd.b | |- B = ( Base ` R ) |
|
| 2 | domnmuln0rd.t | |- .x. = ( .r ` R ) |
|
| 3 | domnmuln0rd.z | |- .0. = ( 0g ` R ) |
|
| 4 | domnmuln0rd.1 | |- ( ph -> R e. Domn ) |
|
| 5 | domnmuln0rd.2 | |- ( ph -> X e. B ) |
|
| 6 | domnmuln0rd.3 | |- ( ph -> Y e. B ) |
|
| 7 | domnmuln0rd.4 | |- ( ph -> ( X .x. Y ) =/= .0. ) |
|
| 8 | 1 2 3 | domneq0 | |- ( ( R e. Domn /\ X e. B /\ Y e. B ) -> ( ( X .x. Y ) = .0. <-> ( X = .0. \/ Y = .0. ) ) ) |
| 9 | 4 5 6 8 | syl3anc | |- ( ph -> ( ( X .x. Y ) = .0. <-> ( X = .0. \/ Y = .0. ) ) ) |
| 10 | 9 | necon3abid | |- ( ph -> ( ( X .x. Y ) =/= .0. <-> -. ( X = .0. \/ Y = .0. ) ) ) |
| 11 | 7 10 | mpbid | |- ( ph -> -. ( X = .0. \/ Y = .0. ) ) |
| 12 | ioran | |- ( -. ( X = .0. \/ Y = .0. ) <-> ( -. X = .0. /\ -. Y = .0. ) ) |
|
| 13 | 11 12 | sylib | |- ( ph -> ( -. X = .0. /\ -. Y = .0. ) ) |
| 14 | neqne | |- ( -. X = .0. -> X =/= .0. ) |
|
| 15 | neqne | |- ( -. Y = .0. -> Y =/= .0. ) |
|
| 16 | 14 15 | anim12i | |- ( ( -. X = .0. /\ -. Y = .0. ) -> ( X =/= .0. /\ Y =/= .0. ) ) |
| 17 | 13 16 | syl | |- ( ph -> ( X =/= .0. /\ Y =/= .0. ) ) |