def gen_expansions(value, proof_state):
for (prob_expr, inject) in E.gen_matches(E.is_prob, proof_state.root_expr):
prob_vars = get_variable_order(prob_expr)
prob_values = [proof_state.bindings[v] for v in prob_vars]
if value in prob_values:
continue
# prob([x],[w]) -> sigma(y, product([prob([x], [y, w]), p([y], [w])]))
i = new_variable_name(proof_state.bindings)
v_i = E.v(i)
alpha_left = tuple(prob_expr[1])
alpha_right = (v_i, ) + tuple(prob_expr[2])
alpha = E.prob(alpha_left, alpha_right)
beta_left = (v_i, )
beta_right = tuple(prob_expr[2])
beta = E.prob(beta_left, beta_right)
expr_prime = E.sigma(v_i, E.product([alpha, beta]))
succ_length = proof_state.length + 1
succ_heuristic = 0
succ_bindings = dict(proof_state.bindings)
succ_bindings[i] = value
succ_root_expr = inject(expr_prime)
succ_comment = 'conditioned %s on %s' % (
pleasantly_fmt(proof_state.bindings, prob_expr),
make_canonical_variable_name(value))
succ_proof_state = ProofState(succ_length, succ_heuristic, succ_bindings, succ_root_expr,
parent=proof_state, comment=succ_comment)
yield succ_proof_state
def test_gen_matches():
root_expr = prob([v('z')], [do(v('x'))])
matches = list(gen_matches(is_v, root_expr))
assert len(matches) == 2
match_a, match_b = matches
assert match_a[0] == v('z')
assert match_b[0] == v('x')
# test substitution machinery
assert match_a[1]('banana') == prob(['banana'], [do(v('x'))])
assert match_b[1]('rambutan') == prob([v('z')], [do('rambutan')])
def test_gen_matches():
root_expr = prob([v("z")], [do(v("x"))])
matches = list(gen_matches(is_v, root_expr))
assert len(matches) == 2
match_a, match_b = matches
assert match_a[0] == v("z")
assert match_b[0] == v("x")
# test substitution machinery
assert match_a[1]("banana") == prob(["banana"], [do(v("x"))])
assert match_b[1]("rambutan") == prob([v("z")], [do("rambutan")])
def test_gen_matches_deep():
# sigma_y { p(x|y,do(z)) * p(y|do(z)) }
root_expr = sigma(v("y"), product([prob([v("x")], [v("y"), do(v("z"))]), prob([v("y")], [do(v("z"))])]))
matches = list(gen_matches(is_v, root_expr))
assert len(matches) == 6
expr, inject = matches[3]
assert expr == v("z")
root_expr_prime = inject("walrus")
assert root_expr_prime == sigma(
v("y"), product([prob([v("x")], [v("y"), do("walrus")]), prob([v("y")], [do(v("z"))])])
)
def test_gen_matches_deep():
# sigma_y { p(x|y,do(z)) * p(y|do(z)) }
root_expr = sigma(
v('y'),
product([
prob([v('x')], [v('y'), do(v('z'))]),
prob([v('y')], [do(v('z'))])
]))
matches = list(gen_matches(is_v, root_expr))
assert len(matches) == 6
expr, inject = matches[3]
assert expr == v('z')
root_expr_prime = inject('walrus')
assert root_expr_prime == sigma(
v('y'),
product([
prob([v('x')], [v('y'), do('walrus')]),
prob([v('y')], [do(v('z'))])
]))
def gen_moves(root_expr):
for (expr, expr_inject) in gen_matches(expr_predicate, root_expr):
for site in gen_target_sites(expr):
target, site_inject, left, vs, dos = site
inject = compose(expr_inject, site_inject)
yield (target, inject, left, vs, dos, expr)
def gen_moves(root_expr):
for (expr, expr_inject) in gen_matches(expr_predicate, root_expr):
for site in gen_target_sites(expr):
target, site_inject, left, vs, dos = site
inject = compose(expr_inject, site_inject)
yield (target, inject, left, vs, dos, expr)
def count_sigmas(expr):
return len(list(E.gen_matches(E.is_sigma, expr)))
