formalizing desargues' theorem in coq using ranks
Formalizing geometry theorems in a proof assistant like Coq is challenging. As emphasized in the literature, the non-degeneracy conditions leads to technical proofs. In addition, when considering higher-dimensions, the amount of incidence relations (e.g. point-line, point-plane, line-plane) induce numerous technical lemmas. In this paper, we present an original approach based on the notion of rank which allows to describe incidence and non-incidence relations such as equality, collinearity and coplanarity homogeneously. It allows to carry out proofs in a more systematic way. To validate this approach, we formalize in Coq (using only ranks) one of the fundamental theorems of the projective space, namely Desargues' theorem.
formalization desargues coq rank projective geometry