def hanoi():
from hornet import Database, pyfunc, _, greater, let, cut
from hornet.symbols import play_hanoi, move, M, N, From, With, To
@pyfunc
def show_move(N, From, To, With):
towers[To()].push(towers[From()].pop())
db = Database()
db.tell(
play_hanoi(N, From, To, With) <<
greater(N, 0) &
move(N, From, To, With),
move(1, From, To, _)[show_move] << cut,
move(N, From, To, With) <<
let(M, N - 1) &
move(M, From, With, To) &
move(1, From, To, _) &
move(M, With, To, From),
)
for subst in db.ask(play_hanoi(6, 0, 1, 2)):
print('Yes.')
break
else:
print('No.')
def test_resolver():
from pprint import pprint
from hornet import Database
from hornet.symbols import _, f, g, h, a, b, c, X, Y, Z
db = Database()
db.tell(
a,
f(a, b, c),
f(a, a, a),
f(c, b, a),
f(X, Y, Z) << g(X, a) & h(Y, b) & c,
g(X, X, Y),
h(X) << g(X, a, _) | g(X, b, _),
)
pprint(db)
for subst in db.ask(g(a, Z, Z)):
pprint(subst)
for subst in db.ask(g([a, b | c], Z, Z)):
pprint(subst)
for subst in db.ask(f(X, Y, Z)):
pprint(subst)
for subst in db.ask(h(X)):
pprint(subst)
for subst in db.ask(~g(a, b, Y)):
print(subst)