Collinearity
= Collinearity
{wiki}
Points are collinear when they lie on a single <line>. Two <vectors> are collinear when their <linear span> has <dimension> at most one. For a nonzero vector $v$, this means that the other vector is $\lambda v$ for some <scalar> $\lambda$. This algebraic convention includes the zero vector; the directional use of “parallel” sometimes assumes both vectors are nonzero.