“The creation of art is notoriously difficult to depict on stage (as in film), so leeway must be allowed those who would evoke this slow and tortuous process in a brief, digestible narrative. But “Seminar” seems to be almost nothing but shortcuts, and that includes the ways it defines and manipulates its characters. Full of efficiently mapped reversals and revelations, the play feels as if it were written according to some literary equivalent of a mileage-saving GPS device.”