[metapost] turningnumber revisited

[luigi scarso]

On Mon, Jun 27, 2011 at 10:52 AM,  <laurent at math.toronto.edu> wrote:
>     There is a daring statement in the "Metafont
> book" page 111:
>
>  << Every cyclic path has a {\sl turning number\/} >>
>
> This statement alarms me.  What is the turning number
> of the cyclic path
>
>    A -- B -- cycle         ?
Perhaps this can help (from mf.web)
@ The |make_spec| routine has an interesting side effect, namely to set
the global variable |turning_number| to the number of times the tangent
vector of the given cyclic path winds around the origin.

Do you have some explicit examples of  paths with strange turning numbers ?

-- 
luigi