[metapost] turningnumber revisited

[laurent at math.toronto.edu]

Hi all,

Which MP (or MF) paths are now claimed to have a well
defined 'turningnumber'? And what are the properties
asserted for the turning number function?
And who cares?

 Taco > It should be something simple indeed.

Laurent S.

PS. I could venture reasonable answers for those paths
that are end-to-end composed of nowhere singular
b'eziers paths that abut at nonzero angles.