Metamath Proof Explorer


Theorem adddirp1d

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

Ref Expression
Hypotheses adddirp1d.a φA
adddirp1d.b φB
Assertion adddirp1d φA+1B=AB+B

Proof

Step Hyp Ref Expression
1 adddirp1d.a φA
2 adddirp1d.b φB
3 1cnd φ1
4 1 3 2 adddird φA+1B=AB+1B
5 2 mullidd φ1B=B
6 5 oveq2d φAB+1B=AB+B
7 4 6 eqtrd φA+1B=AB+B