Here is a corrected version:
import itertools
n = 4
formula = [[1, -2, 3], [-1, 3], [-3], [2, 3]]
allorderings = itertools.product ([False, True], repeat = n)
for potential in allorderings:
print ("Initial values:", potential)
allclauses = []
for clause in formula:
curclause = []
for item in clause:
x = potential[abs (item) - 1]
curclause.append (x if item > 0 else not x)
cal = any (curclause)
allclauses.append (cal)
print ("Clauses:", allclauses)
formcheck = all (allclauses)
print ("This combination works:", formcheck)
Points to consider:
Instead of introducing some complex — and also wrong — logic to find the conjunction and disjunction, you can use
any
andall
. That's cleaner and less prone to bugs.The natural object to loop over is
itertools.product([False, True], repeat = n)
, that is, the set[False, True]
of possible boolean values raised to the power ofn
. In other words, the Cartesian product ofn
copies of[False, True]
. Here is the documentation for itertools.product.I introduced a bit more output to see how things are going. Here is the output I get with Python3 (Python2 adds parentheses but prints essentially the same):
Initial values: (False, False, False, False)
Clauses: [True, True, True, False]
This combination works: False
Initial values: (False, False, False, True)
Clauses: [True, True, True, False]
This combination works: False
Initial values: (False, False, True, False)
Clauses: [True, True, False, True]
This combination works: False
Initial values: (False, False, True, True)
Clauses: [True, True, False, True]
This combination works: False
Initial values: (False, True, False, False)
Clauses: [False, True, True, True]
This combination works: False
Initial values: (False, True, False, True)
Clauses: [False, True, True, True]
This combination works: False
Initial values: (False, True, True, False)
Clauses: [True, True, False, True]
This combination works: False
Initial values: (False, True, True, True)
Clauses: [True, True, False, True]
This combination works: False
Initial values: (True, False, False, False)
Clauses: [True, False, True, False]
This combination works: False
Initial values: (True, False, False, True)
Clauses: [True, False, True, False]
This combination works: False
Initial values: (True, False, True, False)
Clauses: [True, True, False, True]
This combination works: False
Initial values: (True, False, True, True)
Clauses: [True, True, False, True]
This combination works: False
Initial values: (True, True, False, False)
Clauses: [True, False, True, True]
This combination works: False
Initial values: (True, True, False, True)
Clauses: [True, False, True, True]
This combination works: False
Initial values: (True, True, True, False)
Clauses: [True, True, False, True]
This combination works: False
Initial values: (True, True, True, True)
Clauses: [True, True, False, True]
This combination works: False