Hi. The following bug in abcl breaks CL-Yacc. Consider the following: (defstruct item a) (defstruct (item1 (:include item) (:conc-name item-)) b) (defun abcl-bug () (item-a (make-item :a 'a))) According to the last paragraph of the description of the description of :conc-name in the defstruct section of the CLHS, this is legal. However, abcl says: ABCL-BUG(6): (abcl-bug) #<THREAD "interpreter" {108F8E0}>: Debugger invoked on condition of type SIMPLE-TYPE-ERROR The value #<ABCL-BUG::ITEM {537935}> is not of type ABCL-BUG::ITEM1. Restarts: 0: TOP-LEVEL Return to top level. [1] ABCL-BUG(7): Regards, Juliusz