Modeling planar configurations

During the part fev ywrr we have introduced two c~binatorial objocte, allovable l equencee and lubda utricee, which encode veriour klndm of geometric informtioa about configurrtlone of points and their dualr, arrangement8 of linea. In the ~88~ of lambda matrices the encoding worke equally well in higher dimnaionr. The kind of Information thst ie encoded, incidence end order propertier, 18 rich enough so thst even though the object 18 mm8 general then 8n l c rum1 configuration it la porrlble (and derirable) to tmnef arm intereating geometric problew Into problw about the object it8elf. In thir way rho object 18 8 “modal” for the geoutrlc configuretion.