[174]Prerequisites:[172],[0NZ].If \(Aβ β^ n\) is convex, \(xβ {{A}^\circ }\) and \(zβ β A\) then the segment that connects them is contained in \({{A}^\circ }\), except possibly for the extreme \(z\) (i.e. \(β tβ(0,1), tx+(1-t)zβ {{A}^\circ }\)).