from pyDatalog.pyDatalog import create_terms, load, ask, assert_fact

create_terms('X, croakes, eatFlies, green, frog, sings, chirps, yellow, canary')

load("""

""")

frog(X) <= croakes(X) & eatFlies(X)

canary(X) <= sings(X) & chirps(X)

green(X) <= frog(X)

yellow(X) <= canary(X)

assert_fact('croakes','fritz' )

assert_fact('eatFlies','fritz' )

+sings('titi')

+chirps('titi')

+frog('Toto')

# assert_fact('sings','Jean' )

# assert_fact('chirps','Jean' )

query = 'yellow(X)'

answers = ask(query).answers

print(answers)

print(ask('frog(X)'))

print(ask("frog('fritz')"))