plangeo6 plangeo6.ocd 2006-06-01 experimental 2004-06-01 0 3 plangeo1 This CD defines symbols for planar Euclidean geometry related to conics. amc: 18 March 2004 added are_on_conic conic The symbol represents a conic. The conic may be subject to constraints. The conic G, incident to A,B,C,D and E is given by are_on_conic The symbol is a boolean n-ary function. Its arguments should be points. When applied to a sequence of points, its evaluated to true if and only if there is a conic on which all arguments lie. If G is the conic determined by A,B,C,D, and E, whereas F is a point incident with G, then A,B,C,D, E, and F are on a conic.