Is there a function to map faces of a cone its dual?
Suppose C
is a full dimensional pointed rational polyhedral cone with vertex at the origin. Then there is a correspondence between faces of C
and faces of C.dual()
given by
F -> Fd := { y in C.dual() | <y, x> = 0 for all x in F }
This correspondence satisfies
dim(F)+dim(Fd)=dim(C)
I want to define the function (or dictionary) in sage that maps each face in C.face_lattice()
to its corresponding face in C.dual().face_lattice()
. Does this function exist in sage?