def __init__(self, domain, properties, binary_rels, valuation):
self._domain = domain
self._properties = properties
self._binary_rels = binary_rels
self._model = nltk.Model(set(domain), nltk.Valuation(valuation))
self._valuation = valuation
self._preds = dict()
self._pred_sats = dict()
for (pred, sats) in valuation:
self._preds[pred] = sats
if pred in binary_rels:
sat_map_0 = dict()
sat_map_1 = dict()
for sat in sats:
if sat[0] not in sat_map_0:
sat_map_0[sat[0]] = set([])
if sat[1] not in sat_map_1:
sat_map_1[sat[1]] = set([])
sat_map_1[sat[1]].add(sat[0])
sat_map_0[sat[0]].add(sat[1])
self._pred_sats[pred] = (sat_map_0, sat_map_1)
elif pred in properties:
sat_set = set([])
for sat in sats:
sat_set.add(sat)
self._pred_sats[pred] = sat_set
def logic_parser():
lp = nltk.LogicParser()
SnF = lp.parse('SnF')
NotFnS = lp.parse('-FnS')
R = lp.parse('SnF -> -FnS')
# prover = nltk.Prover9()
# print prover.prove(NotFnS, [SnF, R])
val = nltk.Valuation([('P', True), ('Q', True), ('R', False)])
dom = set([])
g = nltk.Assignment(dom)
m = nltk.Model(dom, val)
print "eval(P&Q)=", m.evaluate('(P & Q)', g)
print "eval -(P&Q)=", m.evaluate('-(P & Q)', g)
print "eval(P&R)=", m.evaluate('(P & R)', g)
print "eval(-(P|R))=", m.evaluate('-(P | R)', g)
read_expr('P & Q')
read_expr('P | (R -> Q)')
read_expr('P <-> -- P')
lp = nltk.sem.Expression.fromstring
SnF = read_expr('SnF')
NotFnS = read_expr('-FnS')
R = read_expr('SnF -> -FnS')
prover = nltk.Prover9()
prover.config_prover9(r'D:\Program Files\LADR1007B-win\bin')
prover.prove(NotFnS, [SnF, R])
val = nltk.Valuation([('P', True), ('Q', True), ('R', False)])
val['P']
dom = set()
g = nltk.Assignment(dom)
m = nltk.Model(dom, val)
print(m.evaluate('(P & Q)', g))
print(m.evaluate('-(P & Q)', g))
print(m.evaluate('(P & R)', g))
print(m.evaluate('(P | R)', g))
##一阶逻辑
read_expr = nltk.sem.Expression.fromstring
expr = read_expr('walk(angus)', type_check=True)
import nltk
value = nltk.Valuation([('X', True), ('Y', False), ('Z', True)])
print(value['Z'])
domain = set()
v = nltk.Assignment(domain)
u = nltk.Model(domain, value)
print(u.evaluate('(X & Y)', v))
print(u.evaluate('-(X & Y)', v))
print(u.evaluate('(X & Z)', v))
print(u.evaluate('(X | Y)', v))
propositon_Q = 'He will eat a sandwich'
p_statuses = [False, False, True, True]
q_statuses = [False, True, False, True]
conjunction = '(P & Q)'
disjunction = '(P | Q)'
implication = '(P -> Q)'
equivalence = '(P <-> Q)'
expressions = [conjunction, disjunction, implication, equivalence]
results = []
for status_p, status_q in zip(p_statuses, q_statuses):
dom = set([])
val = nltk.Valuation([(symbol_P, status_p),
(symbol_Q, status_q)])
assignments = nltk.Assignment(dom)
model = nltk.Model(dom, val)
row = [status_p, status_q]
for expression in expressions:
result = model.evaluate(expression, assignments)
row.append(result)
results.append(row)
columns = [symbol_P, symbol_Q, conjunction,
disjunction, implication, equivalence]
result_frame = pd.DataFrame(results, columns=columns)
print ('P:', proposition_P)
print ('Q:', propositon_Q)
print ()