Page C130, line 26 `z0 .. z1{curl 1}&{curl 1}z1 .. z2 .. cycle'. should be `z0 .. z1{curl 1} & {curl 1}z1 .. z2 .. cycle'. Page C298, line 13 --subpath(t,T) of r shifted .5up -- cycle) enddef; should be -- subpath(t,T) of r shifted .5up -- cycle) enddef;