def transversal_yield_lv(sets: List[PySet], transversal: Tuple[PyValue, PyValue, PyValue]):
"""
transversal is a tuple of length len(sets).
Initially it consists of uninstaniated PyValues.
When all the PyValues are instantiated, it is yielded as the answer.
"""
remaining_indices = uninstantiated_indices_lv(transversal)
if not remaining_indices:
yield transversal
else:
if propagate:
# If we are propagating, we will have removed used values from all the sets.
# If any of those sets are now empty but are associated with
# an uninstantiated position in transversal, fail;
empty_sets = [sets[indx].is_empty() for indx in remaining_indices]
if any(empty_sets):
return None
next_index = min(remaining_indices,
key=lambda indx: indx if not smallest_first else len(sets[indx]))
# T_next is the PyValue to be instantiated this time around.
T_next = transversal[next_index]
used_values = PyList([transversal[i] for i in range(len(transversal)) if i not in remaining_indices])
for _ in member(T_next, sets[next_index]):
for _ in fails(member)(T_next, used_values):
new_sets = sets if not propagate else [set.discard(T_next) for set in sets]
yield from transversal_yield_lv(new_sets, transversal)
def transversal_yield_lv(sets: List[PyList], so_far: PyList, Answer: Var):
print(f'sets/[{", ".join([str(S) for S in sets])}]; so_far_reversed/{reversed(so_far)}')
if not sets:
yield from unify(reversed(so_far), Answer)
else:
[S, *Ss] = sets
X = Var( )
for _ in member(X, S):
for _ in fails(member)(X, so_far):
yield from transversal_yield_lv(Ss, PyList([X]) + so_far, Answer)
def transversal_yield_lv(Sets: List[PyList], Partial_Transversal: PyList,
Complete_Transversal: Var):
print(
f'Sets/[{", ".join([str(S) for S in Sets])}]; Partial_Transversal/{Partial_Transversal}'
)
if not Sets:
yield from unify(Partial_Transversal, Complete_Transversal)
else:
(S, Ss) = (Sets[0], Sets[1:])
Element = Var()
for _ in member(Element, S):
for _ in fails(member)(Element, Partial_Transversal):
yield from transversal_yield_lv(
Ss, Partial_Transversal + PyList([Element]),
Complete_Transversal)
def tnvsl_dfs_gen_lv(sets, tnvsl):
var_indxs = uninstan_indices_lv(tnvsl)
if not var_indxs: yield tnvsl
else:
empty_sets = [sets[indx].is_empty() for indx in var_indxs]
if any(empty_sets): return None
nxt_indx = min(var_indxs, key=lambda indx: len(sets[indx]))
used_values = PyList(
[tnvsl[i] for i in range(len(tnvsl)) if i not in var_indxs])
T_Var = tnvsl[nxt_indx]
for _ in member(T_Var, sets[nxt_indx]):
for _ in fails(member)(T_Var, used_values):
new_sets = [set.discard(T_Var) for set in sets]
yield from tnvsl_dfs_gen_lv(new_sets, tnvsl)
def clue_2(self, Stdnts):
""" Emmy studies either Math or Bio. """
# Create Major as a local logic variable.
Major = Var()
for _ in member(Stdnt(name='Emmy', major=Major), Stdnts):
yield from member(Major, PyList(['Math', 'Bio']))
def clue_13(self, Houses: SuperSequence):
""" 13. The Japanese smoke Parliament. """
yield from member(House(nationality='Japanese', smoke='Parliament'),
Houses)
def clue_12(self, Houses: SuperSequence):
""" 12. The Lucky smokers drink juice. """
yield from member(House(drink='juice', smoke='Lucky'), Houses)
def clue_7(self, Houses: SuperSequence):
""" 7. They smoke Kool in the yellow house. """
yield from member(House(smoke='Kool', color='yellow'), Houses)
def clue_6(self, Houses: SuperSequence):
""" 6. The Old Gold smokers have snails. """
yield from member(House(smoke='Old Gold', pet='snails'), Houses)
def clue_3(self, Houses: SuperSequence):
""" 3. They drink coffee in the green house. """
yield from member(House(drink='coffee', color='green'), Houses)
def clue_2(self, Houses: SuperSequence):
""" 2. The Spanish have a dog. """
yield from member(House(nationality='Spanish', pet='dog'), Houses)
def clue_1(self, Houses: SuperSequence):
""" 1. The English live in the red house. """
yield from member(House(nationality='English', color='red'), Houses)
def clue_2(self, Students: SuperSequence):
""" 2. Amy studies either Philosophy or English. """
# Create Major as a local logic variable.
Major = PyValue()
for _ in member(Student(name='Amy', major=Major), Students):
yield from member(Major, self.ListType(['Philosophy', 'English']))
lambda: unify_pairs([(Xs, emptyLinkedList), (Ys, Zs)]),
# Clause 2.
lambda: forall([
lambda: unify_pairs([(Xs, LinkedList((XZ_Head, Xs_Tail))),
(Zs, LinkedList((XZ_Head, Zs_Tail)))]),
lambda: append(Xs_Tail, Ys, Zs_Tail)
])
]):
yield
if __name__ == '__main__':
print(emptyLinkedList)
E = PyValue(3)
for _ in member(E, emptyLinkedList):
print(f'Error: should not get here.')
A = LinkedList((Var(), Var()))
A112 = A[4:11:2]
A37 = A[3:7]
print(f'\nA: {A}\nA[3:7]: {A37}\nA[4:11:2]: {A112}')
for _ in unify(A37, LinkedList('ABCD')):
print(f'\nA: {A}\nA[3:7]: {A37}\nA[4:11:2]: {A112}')
print()
print(f'A[:4]: {A[:4]}')
A_tail = A.tail()
print(f'A.tail()[:3]: {A_tail[:3]}')
print(f'A.tail().tail()[:2]: {A.tail().tail()[:2]}')
def clue_4(self, Houses: SuperSequence):
""" 4. The Ukrainians drink tea. """
yield from member(House(nationality='Ukrainians', drink='tea'), Houses)
def zebra_problem(Houses):
for _ in forall([
# 1. The English live in the red house.
lambda: member(House(nationality='English', color='red'), Houses),
# lambda: print_SF(f'After 1: {Houses}', 'Succeed'),
# 2. The Spanish have a dog.
lambda: member(House(nationality='Spanish', pet='dog'), Houses),
# lambda: print_SF(f'After 2: {Houses}', 'Succeed'),
# 3. They drink coffee in the green house.
lambda: member(House(drink='coffee', color='green'), Houses),
# lambda: print_SF(f'After 3: {Houses}', 'Succeed'),
# 4. The Ukrainians drink tea.
lambda: member(House(nationality='Ukrainians', drink='tea'), Houses
),
# lambda: print_SF(f'After 4: {Houses}', 'Succeed'),
# 5. The green house is immediately to the right of the white house.
lambda: is_contiguous_in(
[House(color='white'),
House(color='green')], Houses),
# lambda: print_SF(f'After 5: {Houses}', 'Succeed'),
# 6. The Old Gold smokers have snails.
lambda: member(House(smoke='Old Gold', pet='snails'), Houses),
# lambda: print_SF(f'After 6: {Houses}', 'Succeed'),
# 7. They smoke Kool in the yellow house.
lambda: member(House(smoke='Kool', color='yellow'), Houses),
# lambda: print_SF(f'After 7: {Houses}', 'Succeed'),
# 8. They drink milk in the middle house.
# Note the use of a slice. Houses[2] picks the middle house.
lambda: unify(House(drink='milk'), Houses[2]),
# lambda: print_SF(f'After 8: {Houses}', 'Succeed'),
# 9. The Norwegians live in the first house on the left.
lambda: unify(House(nationality='Norwegians'), Houses.head()),
# lambda: print_SF(f'After 9: {Houses}', 'Succeed'),
# 10. The Chesterfield smokers live next to the fox.
lambda: next_to(House(smoke='Chesterfield'), House(pet='fox'),
Houses),
# lambda: print_SF(f'After 10: {Houses}', 'Succeed'),
# 11. They smoke Kool in the house next to the horse.
lambda: next_to(House(smoke='Kool'), House(pet='horse'), Houses),
# lambda: print_SF(f'After 11: {Houses}', 'Succeed'),
# 12. The Lucky smokers drink juice.
lambda: member(House(drink='juice', smoke='Lucky'), Houses),
# lambda: print_SF(f'After 12: {Houses}', 'Succeed'),
# 13. The Japanese smoke Parliament.
lambda: member(House(nationality='Japanese', smoke='Parliament'),
Houses),
# lambda: print_SF(f'After 13: {Houses}', 'Succeed'),
# 14. The Norwegians live next to the blue house.
lambda: next_to(House(nationality='Norwegians'), House(color='blue'
), Houses),
# lambda: print_SF(f'After 14: {Houses}', 'Succeed'),
# Fill in unmentioned properties.
lambda: members([House(pet='zebra'),
House(drink='water')], Houses),
]):
yield
=> [1, 4, 3]
"""
"""
transversal_prolog(sets, so_far, _Answer) :-
reverse(so_far, so_far_reversed),
writeln('sets'/sets;' so_far_reversed'/so_far_reversed),
fail.
transversal_prolog([], so_far, Answer) :-
reverse(so_far, Answer),
format(' '),
writeln('Answer '=Answer), nl.
transversal_prolog([S|Ss], so_far, Answer) :-
member(X, S),
\+ member(X, so_far),
transversal_prolog(Ss, [X|so_far], Answer).
transversal_prolog(Sets, So_Far, _Answer) :-
reverse(So_Far, So_Far_Reversed),
writeln('Sets'/Sets;' So_Far_Reversed'/So_Far_Reversed),
fail.
transversal_prolog([], So_Far, Answer) :-
reverse(So_Far, Answer),
