 
 vec3 Difference(vec3 Cb, vec3 Cs) {
     return abs(Cb - Cs);
-}
-
-vec3 Exclusion(vec3 Cb, vec3 Cs) {
-    return Cb + Cs - 2.0 * Cb * Cs;
 }
 
 // These functions below are taken from the spec.

        case MixBlendMode_Difference:
            result.rgb = Difference(Cb.rgb, Cs.rgb);
            break;
        case MixBlendMode_Exclusion:
            result.rgb = Exclusion(Cb.rgb, Cs.rgb);
            break;
        case MixBlendMode_Hue:
            result.rgb = Hue(Cb.rgb, Cs.rgb);
            break;

        case MixBlendMode_Multiply:
            result.rgb = Multiply(Cb.rgb, Cs.rgb);
            break;
        case MixBlendMode_Overlay:
            // Overlay is inverse of Hardlight
            result.rgb = HardLight(Cs.rgb, Cb.rgb);
