Description: Equality deduction for product. (Contributed by Scott Fenton, 4-Dec-2017)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | prodeq12rdv.1 | |- ( ph -> A = B ) | |
| prodeq12rdv.2 | |- ( ( ph /\ k e. B ) -> C = D ) | ||
| Assertion | prodeq12rdv | |- ( ph -> prod_ k e. A C = prod_ k e. B D ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | prodeq12rdv.1 | |- ( ph -> A = B ) | |
| 2 | prodeq12rdv.2 | |- ( ( ph /\ k e. B ) -> C = D ) | |
| 3 | 1 | prodeq1d | |- ( ph -> prod_ k e. A C = prod_ k e. B C ) | 
| 4 | 2 | prodeq2dv | |- ( ph -> prod_ k e. B C = prod_ k e. B D ) | 
| 5 | 3 4 | eqtrd | |- ( ph -> prod_ k e. A C = prod_ k e. B D ) |