i' <- choose (coordmin, coordmax)
j' <- choose (coordmin, coordmax)
k' <- choose (coordmin, coordmax)
fv' <- arbitrary :: Gen FunctionValues
(Positive tet_vol) <- arbitrary :: Gen (Positive Double)
i' <- choose (coordmin, coordmax)
j' <- choose (coordmin, coordmax)
k' <- choose (coordmin, coordmax)
fv' <- arbitrary :: Gen FunctionValues
(Positive tet_vol) <- arbitrary :: Gen (Positive Double)