thvariant="italic">nd</mi>
                    </msub>
                    <msub><mi mathvariant="italic">y</mi>
                    <mi mathvariant="italic">nd</mi>
                    </msub>
                </mfenced>
            </math>
            be normalized device coordinates.
            Then the window coordinates
            <math overflow="scroll">

                <mfenced open="(" close=")">
                    <msub><mi mathvariant="italic">x</mi>
                    <mi mathvariant="italic"