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 | |