In system 29.95 NWS, with microcode 669, on Xerox Machine 1: I think it is a misfeature that the following does not work. (defstruct (foo) ((a 10))) [ or (defstruct (foo) ((a 10 0))) ] (make-foo) Admittedly (defstruct (foo :fixnum) ((a 10))) (make-foo) works, but ...