def test_exhaustive_consistent():
# check basic consistency
assert consistent(var('a'), var('b'), sequential('a', 'b'))
# see how long a causal loop can be before transitivity stops working
for i in range(1, 5):
clauses = [sequential(to_char(i), 'a')] + chain(i)
assert not consistent(and_(*clauses), exhaustive=True)
def test_occurrence():
occ = occurrence(relationships([simultaneous('a', 'b')]))
print('occurrence: ', occ)
formula = and_(simultaneous('a', 'b'), not_(var('a')), *occ)
print('formula: ', formula)
s = formula.sat()[1]
if s:
print('solution: ', [k for k, v in s.items() if v])
assert not s
def test_timeline():
statements = [simultaneous('a', 'b'), sequential('b', 'a')]
t = timeline(relationships(statements))
print('timeline: ', t)
formula = and_(var('a'), var('b'), *(t + statements))
print('formula: ', formula)
s = formula.sat()[1]
if s:
print('solution: ', [k for k, v in s.items() if v])
assert not s
def test_transitivity():
def trans(s):
return transitivity(triples(relationships(s)))
statements = [sequential('a', 'b'),
sequential('b', 'c'),
sequential('d', 'e')]
assert len(trans(statements)) == 1
statements += sequential('a', 'c')
assert trans(statements)[0].equiv(
impl(and_(var("a<b"), var("b<c")), var("a<c")))
def test_consistent2():
# see how long a causal loop can be before transitivity stops working
for i in range(1, 5):
clauses = [sequential(to_char(i), 'a')] + chain(i)
assert not consistent(and_(*clauses))
def ordered(*args):
"Arguments happen in some order; not simultaneously"
return and_(
*pairwise(lambda a, b: ~a | ~b
| sequential(a, b)
| sequential(b, a), args))
def simultaneous(a, b, *rest):
if rest:
return and_(*pairwise(simultaneous, (a, b) + rest))
a, b = sorted((a, b)) # make sure we always use pairs in the same order
return var(a + "*" + b)
def sequential(a, b, *rest):
if rest:
return and_(*pairwise(sequential, (a, b) + rest))
return var(a + "<" + b)
def inner(a, b, c):
return and_(impl(fn(a, b) & fn(b, c), fn(a, c)),
impl(simultaneous(a, b) & fn(b, c), fn(a, c)),
impl(fn(a, b) & simultaneous(b, c), fn(a, c)))