+-- | Given in Sorokina and Zeilfelder, p. 79, (2.6). Repeats
+-- 'prop_c0120_identity1' with tetrahedrons 4 and 5.
+-- prop_c0120_identity4 :: Cube -> Bool
+-- prop_c0120_identity4 cube =
+-- sum [trace ("c_t4_0120: " ++ (show tmp1)) tmp1,
+-- trace ("c_t5_0012: " ++ (show tmp2)) tmp2,
+-- trace ("c_t5_0102: " ++ (show tmp3)) tmp3,
+-- trace ("c_t5_1002: " ++ (show tmp4)) tmp4,
+-- trace ("c_t5_0120: " ++ (show tmp5)) tmp5,
+-- trace ("c_t5_1020: " ++ (show tmp6)) tmp6,
+-- trace ("c_t5_1200: " ++ (show tmp7)) tmp7,
+-- trace ("c_t5_0021: " ++ (show tmp8)) tmp8,
+-- trace ("c_t5_0201: " ++ (show tmp9)) tmp9,
+-- trace ("c_t5_2001: " ++ (show tmp10)) tmp10,
+-- trace ("c_t5_0210: " ++ (show tmp11)) tmp11,
+-- trace ("c_t5_2010: " ++ (show tmp12)) tmp12,
+-- trace ("c_t5_2100: " ++ (show tmp13)) tmp13] == 10
+-- -- c t4 0 1 2 0 ~= (c t4 0 0 2 1 + c t5 0 0 1 2) / 2
+-- where
+-- t4 = tetrahedron4 cube
+-- t5 = tetrahedron5 cube
+-- tmp1 = c t4 0 1 2 0
+-- tmp2 = (c t4 0 0 2 1 + c t5 0 0 1 2) / 2
+-- tmp3 = (c t4 0 0 2 1 + c t5 0 1 0 2) / 2
+-- tmp4 = (c t4 0 0 2 1 + c t5 1 0 0 2) / 2
+-- tmp5 = (c t4 0 0 2 1 + c t5 0 1 2 0) / 2
+-- tmp6 = (c t4 0 0 2 1 + c t5 1 0 2 0) / 2
+-- tmp7 = (c t4 0 0 2 1 + c t5 1 2 0 0) / 2
+-- tmp8 = (c t4 0 0 2 1 + c t5 0 0 2 1) / 2
+-- tmp9 = (c t4 0 0 2 1 + c t5 0 2 0 1) / 2
+-- tmp10 = (c t4 0 0 2 1 + c t5 2 0 0 1) / 2
+-- tmp11 = (c t4 0 0 2 1 + c t5 0 2 1 0) / 2
+-- tmp12 = (c t4 0 0 2 1 + c t5 2 0 1 0) / 2
+-- tmp13 = (c t4 0 0 2 1 + c t5 2 1 0 0) / 2
+
+-- -- | Given in Sorokina and Zeilfelder, p. 79, (2.6). Repeats
+-- -- 'prop_c0120_identity1' with tetrahedrons 5 and 6.
+-- prop_c0120_identity5 :: Cube -> Bool
+-- prop_c0120_identity5 cube =
+-- c t5 0 1 2 0 ~= (c t5 0 0 2 1 + c t6 0 0 1 2) / 2
+-- where
+-- t5 = tetrahedron5 cube
+-- t6 = tetrahedron6 cube
+
+
+-- -- | Given in Sorokina and Zeilfelder, p. 79, (2.6). Repeats
+-- -- 'prop_c0120_identity1' with tetrahedrons 6 and 7.
+-- prop_c0120_identity6 :: Cube -> Bool
+-- prop_c0120_identity6 cube =
+-- c t6 0 1 2 0 ~= (c t6 0 0 2 1 + c t7 0 0 1 2) / 2
+-- where
+-- t6 = tetrahedron6 cube
+-- t7 = tetrahedron7 cube
+
+
+-- | Given in Sorokina and Zeilfelder, p. 79, (2.6). See
+-- 'prop_c0120_identity1'.