Description: The product of two nonzero numbers is nonzero. (Contributed by Mario Carneiro, 27-May-2016)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | msq0d.1 | |- ( ph -> A e. CC ) | |
| mul0ord.2 | |- ( ph -> B e. CC ) | ||
| Assertion | mulne0bd | |- ( ph -> ( ( A =/= 0 /\ B =/= 0 ) <-> ( A x. B ) =/= 0 ) ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | msq0d.1 | |- ( ph -> A e. CC ) | |
| 2 | mul0ord.2 | |- ( ph -> B e. CC ) | |
| 3 | mulne0b | |- ( ( A e. CC /\ B e. CC ) -> ( ( A =/= 0 /\ B =/= 0 ) <-> ( A x. B ) =/= 0 ) ) | |
| 4 | 1 2 3 | syl2anc | |- ( ph -> ( ( A =/= 0 /\ B =/= 0 ) <-> ( A x. B ) =/= 0 ) ) |