SCM_CLASS_ABSTRACT  674 src/class.c        case SCM_CLASS_ABSTRACT: return SCM_SYM_ABSTRACT;
SCM_CLASS_ABSTRACT  798 src/class.c        meta->flags = SCM_CLASS_ABSTRACT;
SCM_CLASS_ABSTRACT  530 src/gauche.h       SCM_CLASS_ABSTRACT = 1,
SCM_CLASS_ABSTRACT  657 src/gauche.h                                SCM_CLASS_ABSTRACT,          \