An n-ary logical XOR Q(…) ^ Q(…) ^ … ^ Q(…) should evaluate to true when an odd number of its operands evaluate to true, not when exactly one operand evaluates to true.
An n-ary logical XOR Q(…) ^ Q(…) ^ … ^ Q(…) should evaluate to true when an odd number of its operands evaluate to true, not when exactly one operand evaluates to true.