This is a contribution to the theory of topological vector spaces within the framework of the alternative set theory. Using indiscernibles we will show that every infinite set $uS\subseteq G$ in a biequivalence vector space $\langle W,M,G\rangle$, such that $x-y\notin M$ for distinct $x,y\in u$, contains an infinite independent subset. Consequently, a class $X\subseteq G$ is dimensionally compact iff the $\pi$-equivalence ${\doteq }_M$ is compact on $X$. This solves a problem from the paper [NPZ 1992] by J. Náter, P. Pulmann and the second author.