2-adic unit
= 2-adic unit
{title2=$\mathbb Z_2^\times$}
A 2-adic unit is an odd element of $\mathbb Z_2$. It is a square in $\mathbb Z_2^\times$ exactly when it is congruent to $1$ modulo $8$.
= 2-adic unit
{title2=$\mathbb Z_2^\times$}
A 2-adic unit is an odd element of $\mathbb Z_2$. It is a square in $\mathbb Z_2^\times$ exactly when it is congruent to $1$ modulo $8$.