SCM_API SCM scm_stack_type;
-#define SCM_STACKP(obj) (SCM_STRUCTP (obj) && SCM_EQ_P (SCM_STRUCT_VTABLE (obj), scm_stack_type))
+#define SCM_STACKP(obj) (SCM_STRUCTP (obj) && scm_is_eq (SCM_STRUCT_VTABLE (obj), scm_stack_type))
#define SCM_STACK_LENGTH(stack) (SCM_STACK (stack) -> length)
#define SCM_FRAMEP(obj) \