Sigma function.
        </li>
        <li>
          <b>SIN_VALUES</b> returns some values of the sine function.
        </li>
        <li>
          <b>SIN_DEGREE_VALUES:</b> the sine function with argument in degrees.
        </li>
        <li>
          <b>SIN_POWER_INT_VALUES</b> returns some values of the sine power integral.
        </li>
        <li>
          <b>SINH_VALUES</b> returns some values of the hyperbolic sine function.
        </li>
        <li>
          <b>SIX_J_VALUES</b> returns some 