On Finite $\{2,5\}$-Semiaffine Linear Spaces

Abstract

In this paper, finite $\{2,t\}$-semiaffine linear spaces are investigated. When $t=5$, their parameters are determined, and it is also proved that there is a single finite $\{2,5\}$-semiaffine linear space on $v=20$ points and with constant point degree $7$.