Question

I have this code in Z3 python:

x = Bool('x')
y = Bool('y')
z = Bool('z')
z == (x xor y)
s = Solver()
s.add(z == True)
print s.check()

But this code reports below error when running:

c.py(4): error: invalid syntax

If I replace xor with and, there is no problem. So this means XOR is not supported?

Answer 1

You should use Xor(a, b). Moreover, to create the Z3 expression that represents the formula a and b, we must use And(a, b). In Python, we can’t overload the operators and and or.
Here is an example with the Xor (available online at rise4fun).

x = Bool('x')
y = Bool('y')
z = Xor(x, y)
s = Solver()
s.add(z)
print s.check()
print s.model()