Hi FDs, (i) The upwind example is odd in that the real boundaries are treated in a special way rather than setting the outside value in the same numerical flux as anywhere else; my question is how this can be fixed? So no special terms at the in- and outflow, just specify the outside velocity used. This is imo the proper DG way not was is done now. (ii) Attached my attempt to do a time dependent advection with Crank Nicolson, which works but does not yet give the right answer, in part due to (i). [I don't understand why I have to make my theta variable that a constant but other wise it did not work.] Any suggestions, corrections, also on other silly things done by me? Next step is to extend to system with 3 equations; hence the few extra but unused variables. Thanks, from midnight Seoul in old style Korean guesthouse. Onno ________________________________