Description: Distributive law, plus 1 version. (Contributed by Glauco Siliprandi, 11-Dec-2019)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | adddirp1d.a | ||
| adddirp1d.b | |||
| Assertion | adddirp1d |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | adddirp1d.a | ||
| 2 | adddirp1d.b | ||
| 3 | 1cnd | ||
| 4 | 1 3 2 | adddird | |
| 5 | 2 | mullidd | |
| 6 | 5 | oveq2d | |
| 7 | 4 6 | eqtrd |