Modular addition

Dependencies:

  1. Modular Equivalence

If $a_1 \equiv b_1 \pmod{n}$ and $a_2 \equiv b_2 \pmod{n}$, then $a_1 + a_2 \equiv b_1 + b_2 \pmod{n}$.

Proof

\begin{align} & a_1 \equiv b_1 \wedge a_2 \equiv b_2 \pmod{n} \\ &\Rightarrow n \mid (a_1-b_1) \wedge n \mid (a_2-b_2) \\ &\Rightarrow n \mid (a_1-b_1) + (a_2-b_2) \\ &\Rightarrow n \mid ((a_1+a_2) - (b_1+b_2)) \\ &\Rightarrow a_1+a_2 \equiv b_1+b_2 \pmod{n} \end{align}

Dependency for:

  1. Zn is a ring

Info:

Transitive dependencies:

  1. Modular Equivalence