A Plücker equation for curves in real projective space
J. R. Quine · Proceedings of the American Mathematical Society · 1982
For smooth closed curves in real projective space we write an equation relating the Plücker characteristics, various winding numbers, and a new characteristic involving pairs of points on the line at infinity. This theorem is a generalization of the Umlaufsatz and also relates directly to Plücker’s equations for algebraic curves.