

boundary 
the topological limit of an element 


gap 
the measured distance or angle between two surfaces 
geometry 
the relation between elements taking into account their exact
quantitative measurements 


healing 
the action of filling a gap that may exist between two adjacent
surfaces 


join 
the topological operation in which adjacent surfaces can be assembled
to make up one element 


Connection distance 
the distance between two adjacent edges and beyond which gaps can be
defined as holes 


smoothing 
the action of correcting the geometry of edges 


topology 
the relation between elements abstracted from exact quantitative
measurements 