combineArrayOfGuids.cs

    public Guid combineThose(Guid[] IDs_) {
        
        const int length = 16;

        return IDs_.Aggregate(Guid.Empty, (Accumulate, Current) => {

            var result                = new byte[length];
            var asByteArrayAccumulate = Accumulate.ToByteArray();
            var asByteArrayCurrent    = Current.ToByteArray();

            for (var index = 0; index < length; index++) {

                var byteDate      = asByteArrayAccumulate[index];
                var byteID        = asByteArrayCurrent   [index];
                var byteSurrogate = (byte)(byteID ^ byteDate);

                result.SetValue(byteSurrogate, index);
            }

            return new Guid(result);
        });
    }