Bernard Gibert and Floor van Lamoen,
The parasix configuration and orthocorrespondence,

Forum Geometricorum, 3 (2003) 169--180.

Abstract:
We introduce the parasix configuration, which consists of two congruent triangles. The conditions of these triangles to be orthologic with ABC or a circumcevian triangle, to form a cyclic hexagon, to be equilateral or to be degenerate reveal a relation with orthocorrespondence, as defined in an earlier paper
.

[ps file] [pdf file]