Sentence:  As we have seen, <WSD>points at infinity</WSD> behave as ordinary points: a single line passes through two distinct <WSD>points at infinity</WSD> or through a point in the plane and a <WSD>point at infinity</WSD>. / This representation of the <WSD>points at infinity</WSD> is a difference between the disc and the half-plane models of Poincaré,.... 
Meaning of the word marked with <WSD> tags:  (hyperbolic geometry) An ideal point.