def test_equalities_give_pseudo_boolean_constraints(ls, m):
solver = Solver()
variables = [variable(i) for i in range(len(ls))]
objective = sum(l * v for l, v in zip(ls, variables))
constraint = solver.compile(objective == m)
pseudo_boolean = solver.builder.pseudo_boolean_constraint(
[(l, solver.compile(v)) for l, v in zip(ls, variables)], m, m)
assert constraint == pseudo_boolean
def test_intervals_give_pseudo_boolean_constraints(ls, m, n):
assume(m <= n)
solver = Solver()
variables = [variable(i) for i in range(len(ls))]
objective = sum(l * v for l, v in zip(ls, variables))
constraint = solver.compile((objective >= m) & (objective <= n))
pseudo_boolean = solver.builder.pseudo_boolean_constraint(
[(l, solver.compile(v)) for l, v in zip(ls, variables)], m, n)
assert constraint == pseudo_boolean
def test_upper_bound_gives_pseudo_boolean_constraint(ls, m):
solver = Solver()
variables = [variable(i) for i in range(len(ls))]
objective = sum(l * v for l, v in zip(ls, variables))
constraint = solver.compile(objective <= m)
pseudo_boolean = solver.builder.pseudo_boolean_constraint(
[(l, solver.compile(v)) for l, v in zip(ls, variables)],
-sum(map(abs, ls)), m)
assert constraint == pseudo_boolean
def test_can_multiply_associatively():
solver = Solver()
x = variable('x')
assert solver.compile((x * 2) * 3 == x * 6) is True