Fix completeness issue in SVSP

This commit is contained in:
Brandon Rozek 2025-11-19 15:56:50 -05:00
parent 4179345956
commit bb2024d254

372
vsp.py
View file

@ -3,7 +3,7 @@ Check to see if the model has the variable
sharing property.
"""
from itertools import product, chain, combinations
from typing import List, Optional, Set, Tuple
from typing import List, Generator, Optional, Set, Tuple
from common import set_to_str
from model import (
Model, model_closure, ModelFunction, ModelValue
@ -150,14 +150,15 @@ L: {set_to_str(self.L)}
def powerset_minus_empty(s):
return chain.from_iterable(combinations(s, r) for r in range(1, len(s) + 1))
def find_k1_k2(model, impfunction: ModelFunction,
negation_defined: bool) -> List[Tuple[Set[ModelValue], Set[ModelValue]]]:
def find_k1_k2(model: Model, impfunction: ModelFunction,
negation_defined: bool) -> Generator[Tuple[Set[ModelValue], Set[ModelValue]], None, None]:
"""
Returns a list of possible subalgebra pairs (K1, K2)
for SVSP. This is less efficient than the VSP version
due to interaction with the L and U sets in SVSP.
"""
assert model.ordering is not None, "Expected ordering table in model"
result = []
top = model.ordering.top()
bottom = model.ordering.bottom()
@ -165,39 +166,47 @@ def find_k1_k2(model, impfunction: ModelFunction,
# x -> y does not take a designiated value
I: List[Tuple[ModelValue, ModelValue]] = []
for (x, y) in product(model.designated_values, model.designated_values):
for (x, y) in product(model.carrier_set, model.carrier_set):
if impfunction(x, y) not in model.designated_values:
I.append((x, y))
# Find the subalgebras which falsify implication
for xys in I:
Is = powerset_minus_empty(I)
xi = xys[0]
# Find the subalgebras which falsify implication
for xys in Is:
xs = {xy[0] for xy in xys}
# Discard ({⊥} A', B) subalgebras
if bottom is not None and xi == bottom:
if bottom is not None and bottom in xs:
continue
# Discard ({} A', B) subalgebras when negation is defined
if top is not None and negation_defined and xi == top:
if top is not None and negation_defined and top in xs:
continue
yi = xys[1]
ys = {xy[1] for xy in xys}
# Discard (A, {} B') subalgebras
if top is not None and yi == top:
if top is not None and top in ys:
continue
# Discard (A, {⊥} B') subalgebras when negation is defined
if bottom is not None and negation_defined and yi == bottom:
if bottom is not None and negation_defined and bottom in ys:
continue
# Discard ({a} A', {b} B') subalgebras when a <= b
if model.ordering.is_lt(xi, yi):
continue
order_dependent = False
for (xi, yi) in product(xs, ys):
# Discard ({a} A', {b} B') subalgebras when a <= b
if model.ordering.is_lt(xi, yi):
order_dependent = True
break
# Discard ({a} A', {b} B') subalgebras when b <= a and negation is defined
if negation_defined and model.ordering.is_lt(yi, xi):
order_dependent = True
break
# Discard ({a} A', {b} B') subalgebras when b <= a and negation is defined
if negation_defined and model.ordering.is_lt(yi, xi):
if order_dependent:
continue
# Compute the left closure of the set containing xi under all the operations
@ -236,32 +245,66 @@ def find_k1_k2(model, impfunction: ModelFunction,
break
if falsified:
result.append((carrier_set_left, carrier_set_right))
yield (carrier_set_left, carrier_set_right)
return result
def find_candidate_u_l(
model: Model, impfn: ModelFunction, negfn: Optional[ModelFunction],
K1: Set[ModelValue], K2: Set[ModelValue]) -> Generator[Tuple[Set[ModelValue], Set[ModelValue]], None, None]:
def find_candidate_u_l(model: Model, impfn: ModelFunction, negfn: Optional[ModelFunction]) -> List[Tuple[Set[ModelValue], Set[ModelValue]]]:
result: List[Tuple[Set[ModelValue], Set[ModelValue]]] = []
# Compute I the set of tuples (x, y) where
# x -> y does not take a designiated value
I: List[Tuple[ModelValue, ModelValue]] = []
if negfn is None:
# NOTE: K2 ∩ U = ∅ if ∀x(x → x) ∈ T
# NOTE: K1 ∩ L = ∅ if ∀x(x → x) ∈ T
for (x, y) in product(model.carrier_set - K2, model.carrier_set - K1):
if impfn(x, y) not in model.designated_values:
I.append((x, y))
else:
# NOTE: K1, K2, L, and U are pairwise distinct
CmK1uK2 = model.carrier_set - (K1 | K2)
for (x, y) in product(CmK1uK2, CmK1uK2):
if impfn(x, y) not in model.designated_values:
I.append((x, y))
Is = powerset_minus_empty(I)
F = model.carrier_set - model.designated_values
Us = powerset_minus_empty(model.carrier_set)
Ls = powerset_minus_empty(model.carrier_set)
for (U, L) in product(Us, Ls):
has_double_negation_eq = False
if negfn is not None:
has_double_negation_eq = True
for x in model.carrier_set:
if negfn(negfn(x)) != x:
has_double_negation_eq = False
break
for ULs in Is:
unsat = False
U = set(U)
L = set(L)
U = {UL[0] for UL in ULs}
L = {UL[1] for UL in ULs}
# U and L are distinct
if U.intersection(L):
continue
if has_double_negation_eq:
# NOTE: U is the negation image of L, that is, U = {¬x | x ∈ L}, if ∀x(x = ¬¬x).
U2 = {negfn(x) for x in L}
if U != U2:
continue
yield (U, L)
LFi = F.intersection(L)
# Required property: ∀x ∈ U, y ∈ L(x → y ∈ L ∩ F)
for (x, y) in product(U, L):
# Required property: ∀x ∈ U, y ∈ L(x → y ∈ L ∩ F)
if impfn(x, y) not in LFi:
unsat = True
break
if unsat:
continue
# Required Property: ∀x ∈ L, y ∈ U(x → y ∈ U)
for (x, y) in product(L, U):
if impfn(x, y) not in U:
# Required Property: ∀x ∈ L, y ∈ U(x → y ∈ U)
if impfn(y, x) not in U:
unsat = True
break
@ -288,9 +331,8 @@ def find_candidate_u_l(model: Model, impfn: ModelFunction, negfn: Optional[Model
continue
# Passed all required properties
result.append((U, L))
yield (U, L)
return result
def has_svsp(model: Model, impfn: ModelFunction,
conjfn: Optional[ModelFunction],
@ -309,157 +351,157 @@ def has_svsp(model: Model, impfn: ModelFunction,
starops = [conjfn, disjfn]
K1K2s = find_k1_k2(model, impfn, negfn is not None)
ULs = find_candidate_u_l(model, impfn, negfn)
candidates = ((k1, k2, u, l) for (k1, k2), (u, l) in product(K1K2s, ULs))
for K1, K2, U, L in candidates:
unsat = False
K1Uu = K1 | U
K1Lu = K1 | L
K1LuFi = K1Lu.intersection(F) # (K1 L) ∩ F
K2Uu = K2 | U
K2Lu = K2 | L
K2LuFi = K2Lu.intersection(F) # (K2 L) ∩ F
for K1, K2 in K1K2s:
ULs = find_candidate_u_l(model, impfn, negfn, K1, K2)
for U, L in ULs:
unsat = False
K1Uu = K1 | U
K1Lu = K1 | L
K1LuFi = K1Lu.intersection(F) # (K1 L) ∩ F
K2Uu = K2 | U
K2Lu = K2 | L
K2LuFi = K2Lu.intersection(F) # (K2 L) ∩ F
# (6)
for x, y in product(K1, U):
# b) x → y ∈ K1 U
if impfn(x, y) not in K1Uu:
unsat = True
break
# (6)
for x, y in product(K1, U):
# b) x → y ∈ K1 U
if impfn(x, y) not in K1Uu:
unsat = True
break
# c) y → x ∈ K1 L
if impfn(y, x) not in K1Lu:
unsat = True
break
# c) y → x ∈ K1 L
if impfn(y, x) not in K1Lu:
unsat = True
break
# a) x y, y x, y z ∈ K1 U
for z in U:
for op in starops:
if op is not None:
if op(x, y) not in K1Uu:
unsat = True
break
if op(y, x) not in K1Uu:
unsat = True
break
if op(y, z) not in K1Uu:
unsat = True
break
if unsat:
break
if unsat:
# Verification for these set of matrices failed
break
if unsat:
# Move onto the next candidates K1, K2, U, L
continue
# (7)
for x, y in product(K1, L):
# b) x → y ∈ (K1 L) ∩ F
if impfn(x, y) not in K1LuFi:
unsat = True
break
# c) y → x ∈ K1 U
if impfn(y, x) not in K1Uu:
unsat = True
break
# a) x y, y x, y z ∈ K1 L
for z in L:
for op in starops:
if op is not None:
if op(x, y) not in K1Lu:
unsat = True
break
if op(y, x) not in K1Lu:
unsat = True
break
if op(y, z) not in K1Lu:
unsat = True
break
if unsat:
break
# a) x y, y x, y z ∈ K1 U
for z in U:
for op in starops:
if op is not None:
if op(x, y) not in K1Uu:
unsat = True
break
if op(y, x) not in K1Uu:
unsat = True
break
if op(y, z) not in K1Uu:
unsat = True
break
if unsat:
break
if unsat:
# Verification for these set of matrices failed
break
continue
if unsat:
# Move onto the next candidates K1, K2, U, L
continue
# (8)
for x, y in product(K2, U):
# b) x → y ∈ K2 U
if impfn(x, y) not in K2Uu:
unsat = True
break
# (7)
for x, y in product(K1, L):
# b) x → y ∈ (K1 L) ∩ F
if impfn(x, y) not in K1LuFi:
unsat = True
break
# c) y → x ∈ (K2 L) ∩ F
if impfn(y, x) not in K2LuFi:
unsat = True
break
# c) y → x ∈ K1 U
if impfn(y, x) not in K1Uu:
unsat = True
break
# a) x y, y x, y z ∈ K2 U
for z in U:
for op in starops:
if op is not None:
if op(x, y) not in K2Uu:
unsat = True
break
if op(y, x) not in K2Uu:
unsat = True
break
if op(y, z) not in K2Uu:
unsat = True
break
if unsat:
break
# a) x y, y x, y z ∈ K1 L
for z in L:
for op in starops:
if op is not None:
if op(x, y) not in K1Lu:
unsat = True
break
if op(y, x) not in K1Lu:
unsat = True
break
if op(y, z) not in K1Lu:
unsat = True
break
if unsat:
break
if unsat:
break
continue
if unsat:
continue
# (9)
for x, y in product(K2, L):
# b) x → y ∈ K2 L
if impfn(x, y) not in K2Lu:
unsat = True
break
# (8)
for x, y in product(K2, U):
# b) x → y ∈ K2 U
if impfn(x, y) not in K2Uu:
unsat = True
break
# c) y → x ∈ K2 U
if impfn(y, x) not in K2Uu:
unsat = True
break
# c) y → x ∈ (K2 L) ∩ F
if impfn(y, x) not in K2LuFi:
unsat = True
break
# a) x y, y x, y z ∈ K2 L
for z in L:
for op in starops:
if op is not None:
if op(x, y) not in K2Lu:
unsat = True
break
if op(y, x) not in K2Lu:
unsat = True
break
if op(y, z) not in K2Lu:
unsat = True
break
if unsat:
break
# a) x y, y x, y z ∈ K2 U
for z in U:
for op in starops:
if op is not None:
if op(x, y) not in K2Uu:
unsat = True
break
if op(y, x) not in K2Uu:
unsat = True
break
if op(y, z) not in K2Uu:
unsat = True
break
if unsat:
break
if unsat:
break
if unsat:
continue
# (9)
for x, y in product(K2, L):
# b) x → y ∈ K2 L
if impfn(x, y) not in K2Lu:
unsat = True
break
# c) y → x ∈ K2 U
if impfn(y, x) not in K2Uu:
unsat = True
break
# a) x y, y x, y z ∈ K2 L
for z in L:
for op in starops:
if op is not None:
if op(x, y) not in K2Lu:
unsat = True
break
if op(y, x) not in K2Lu:
unsat = True
break
if op(y, z) not in K2Lu:
unsat = True
break
if unsat:
break
if unsat:
break
if not unsat:
return SVSP_Result(True, model.name, K1, K2, U, L)
if not unsat:
return SVSP_Result(True, model.name, K1, K2, U, L)
return SVSP_Result(False, model.name)