Code 5. Structure of object identification rules.

identification rules library = description of objects; description of objects = object description|description of objects,object description; object description = heading,description of contours[,description of parameters]; heading = ‘#obj’[,space],object name,new line; object name = name; description of contours = component contours[,exclusions]; component contours = declaration of contours[,identification rules]; declaration of contours = ‘contours’,list of contours,new line; exclusions = excluded contours|exclusions,excluded contours; excluded contours = declaration of excluded contours[,identification rules]; declaration of excluded contours =‘ exclude’,list of contours,new line; list of contours = contour declaration|list of contours,‘,’,contour declaration; contour declaration = contour name,‘(‘,contour id,‘)’|contour name,‘,’,contour declaration; contour name = name; contour id = ?contour id in the shape library?|‘any’; identification rules = identification rule|identification rules,identification rule; identification rule = ?topological or logical condition?,new line | auxiliary definition,new line; auxiliary definition = ’aux’,name,’=’,?function returning point or line?; description of parameters = declaration of parameters,calculation rules; declaration of parameters = ‘parameters’,list of parameters,new line; list of parameters = parameter declaration|list of parameters,‘,’,parameter declaration; parameter declaration = parameter name,‘(’,parameter type,‘)’|parameter name,‘,’,parameter declaration; parameter name = name; parameter type = ‘real’|‘point’|‘position’; calculation rules = assignment|calculation rules,assignment; assignment = ?parameter identification?,‘=’,?arithmetic expression?,new line; name = ?string consisting of alphabetic characters and digits?; new line = ?new line character?; space = ?space character?;