+
+
+-- | Given in Sorokina and Zeilfelder, p. 79.
+--prop_c0120_identity1 :: Cube -> Bool
+--prop_c0120_identity1 cube =
+-- c0 ~= (c1 + c2) / 2
+-- where
+-- c0 = trace ("c0 :" ++ (show (c t0 0 1 2 0))) (c t0 0 1 2 0)
+-- c1 = trace ("c1 :" ++ (show (c t0 0 0 2 1))) (c t0 0 0 2 1)
+-- c2 = trace ("c2 :" ++ (show (c t1 0 0 2 1))) (c t1 0 0 2 1)
+-- t0 = tetrahedron0 cube
+-- t1 = tetrahedron1 cube
+
+
+-- | Given in Sorokina and Zeilfelder, p. 78.
+-- prop_cijk1_identity :: Cube -> Bool
+-- prop_cijk1_identity cube =
+-- and [ c t0 i j k 1 ~=
+-- (c t1 (i+1) j k 0) * ((b0 t0) (v3 t1)) +
+-- (c t1 i (j+1) k 0) * ((b1 t0) (v3 t1)) +
+-- (c t1 i j (k+1) 0) * ((b2 t0) (v3 t1)) +
+-- (c t1 i j k 1) * ((b3 t0) (v3 t1)) | i <- [0..2],
+-- j <- [0..2],
+-- k <- [0..2],
+-- i + j + k == 2]
+-- where
+-- t0 = tetrahedron0 cube
+-- t1 = tetrahedron1 cube