Why does LTspice XOR gate have more than two inputs?
From LT wiki:


  The reason that these gates are implemented like that is that this allows one device to act as 2-, 3-, 4- or 5- input gates with true, inverted, or complementary output with no simulation speed penalty for unused terminals.


and


  The exclusive XOR device has non-standard behavior when more than two inputs are used: The output is true only when exactly one of all inputs is true. Use the associative property of XOR's with multiple XOR devices to implement an XOR block with more than two inputs.