Possibly a MiniKanren but I didn't read the book so I'm not sure
x = Var('x')
y = Var('y')
t = (x == 1) & (x == y)
res = run(t)
assert(res['x'] == 1)
assert(res['y'] == 1)There are also relations and disjunctions but probably buggy. The code is very cursed so I'll rewrite it in Scala