(if (= type1 #b11)
nil
(cons type1
- (let ((type2 (lsh (logand #b110000 type-byte) -4)))
+ (let ((type2 (mod (lsh type-byte -4) 4)))
(if (= type2 #b11)
nil
(cons type2
- (let ((type3 (lsh (logand #b1100 type-byte) -2)))
+ (let ((type3 (mod (lsh type-byte -2) 4)))
(if (= type3 #b11)
nil
(cons type3
- (let ((type4 (logand #b11)))
+ (let ((type4 (mod type-byte 4)))
(if (= type4 #b11)
nil
(list type4))))))))))))))