Description: Multiplication by 0 . Theorem I.6 of Apostol p. 18. (Contributed by NM, 15-May-1999) (Revised by Scott Fenton, 3-Jan-2013)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | mul01 | |- ( A e. CC -> ( A x. 0 ) = 0 ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | 0cn | |- 0 e. CC |
|
| 2 | mulcom | |- ( ( A e. CC /\ 0 e. CC ) -> ( A x. 0 ) = ( 0 x. A ) ) |
|
| 3 | 1 2 | mpan2 | |- ( A e. CC -> ( A x. 0 ) = ( 0 x. A ) ) |
| 4 | mul02 | |- ( A e. CC -> ( 0 x. A ) = 0 ) |
|
| 5 | 3 4 | eqtrd | |- ( A e. CC -> ( A x. 0 ) = 0 ) |