z3 无法证明传递身份

Question

我正在尝试 z3 它能做什么。到目前为止一切顺利，但我注意到 z3 在非常琐碎的表达式上失败了：

from z3 import *
a = Int("a")
b = Int("b")
c = Int("c")
prove(((a == b) and (b == c)) == ((a == c) and (c == b)))

$ python p.py
counterexample
[c = 1, b = 0, a = 0]

Answer 1

Python 的 and 不是符号感知的。相反，使用 z3 的 And 方法：

from z3 import *
a = Int("a")
b = Int("b")
c = Int("c")
prove(And(a == b, b == c) == (And(a == c, c == b)))

这会打印：

proved

z3 cannot prove transitive identity