return new Overlay( children, properties);
case OVERLAP:
Figure under = makeChild(0,env,c,properties,childPropsNext);
Figure over = makeChild(1,env,c,properties,childPropsNext);
return new Overlap(under, over, properties);
case SCALE:
PropertyValue<Integer> low = Properties.produceMaybeComputedValue(Types.INT,c.get(0),properties,env);
PropertyValue<Integer> high = Properties.produceMaybeComputedValue(Types.INT,c.get(1),properties,env);
PropertyValue<Integer> selection = Properties.produceMaybeComputedValue(Types.INT,c.get(2),properties,env);