Value and derivative at same boundary pt, "+on" ignored?

For the u’’ +u case just splitting iit up into two vars seems to add enough dof’s
to make it workout.
I guess this is cheating and may have other issues but it looks like it works
although I have not yet tried to extend the “z” results from one run to another using
this ( final “z” and dz as init conitions for next run ). Creating 2 vars sounds bad
except that the nuymber of non-zero matrix elements may not even be all that much
worse.

varf sinewave2([u,du],[v,dv],tgv=-1)
=  int1d(Th)(dx(u)*(v))   + int1d(Th)(-2*pi*du*v)
+  int1d(Th)(dx(du)*(dv))   + int1d(Th)(2*pi*u*dv)
+on(100,du=1)
+on(100,u=1)
;