Metamath Proof Explorer


Theorem adddirp1d

Description: Distributive law, plus 1 version. (Contributed by Glauco Siliprandi, 11-Dec-2019)

Ref Expression
Hypotheses adddirp1d.a φ A
adddirp1d.b φ B
Assertion adddirp1d φ A + 1 B = A B + B

Proof

Step Hyp Ref Expression
1 adddirp1d.a φ A
2 adddirp1d.b φ B
3 1cnd φ 1
4 1 3 2 adddird φ A + 1 B = A B + 1 B
5 2 mulid2d φ 1 B = B
6 5 oveq2d φ A B + 1 B = A B + B
7 4 6 eqtrd φ A + 1 B = A B + B