Why no logical XOR operator

[stt at inmet.inmet.com]

Re: "logical" XOR

As has been pointed out, == and != are essentially
"logical" EQV and XOR, and hence logical XOR is redundant.
The use of unary "!" is necessary if either operand
is not guaranteed to be in the range 0..1.

S. Tucker Taft
Intermetrics, Inc.
Cambridge, MA  02138