The usage of "xor" as "sum modulo 2" is correct if you interpret it as composition of two-argument operators like a^b^c == a^(b^c). It's much easier to use infi

The usage of "xor" as "sum modulo 2" is correct if you interpret it as composition of two-argument operators like a^b^c == a^(b^c). It's much easier to use infix notation with associative operators, so that is likely why the "sum mod 2" interpretation won. The "real xor of >2 arguments" is more useful with a notation like exactly_one(a,b,c).