Vanecek, G.ProtoSolid is a solid modeler that represents solids with planar surfaces and manipulates the solids with regularized set operationa This paper looks at the internal structures and operations of ProtoSolid and is intended as a progranun. user guide. A boundary of a solid is represented by a fedge-based data structure. It is developed in CommonLisp.en-USProtoSolid An Inside Look.Technical Report