def AptIsCoxeterProof.PreApartmentData.toApartmentSystemUnconditional {V : Type} [DecidableEq V] {K : ChamberComplex V} (pre : PreApartmentData K) (hThick : K.IsThick) : ApartmentSystem K

Unconditional construction of an ApartmentSystem from PreApartmentData via the assembled Tits theorem and thickness hypotheses.