diff -r 7ed2e831acd4 -r 865cd526e8b6 linetypes.py
--- a/linetypes.py	Fri May 24 14:18:28 2019 +0200
+++ b/linetypes.py	Fri May 24 14:18:31 2019 +0200
@@ -94,13 +94,13 @@
     def typename(self):
         return 'quadrilateral'
 
-class Contour(LineSegment):
+class ConditionalLine(LineSegment):
     def __init__(self, *, colour, geometry, control_points):
         super().__init__(colour = colour, geometry = geometry)
         self.control_points = control_points
         assert(len(self.control_points) == 2)
     def __repr__(self):
-        return str.format('linetypes.Contour(' \
+        return str.format('linetypes.ConditionalLine(' \
             'colour = {colour!r}, ' \
             'geometry = {geometry!r}, ' \
             'control_points = {control_points!r})', **self.__dict__)