6.1.2490
XOR
x-or
CORE
 
( x1 x2 -- x3 )

x3 is the bit-by-bit exclusive-or of x1 with x2.

Testing:
T{ 0S 0S XOR -> 0S }T
T{ 0S 1S XOR -> 1S }T
T{ 1S 0S XOR -> 1S }T
T{ 1S 1S XOR -> 0S }T