def __init__(self, *args, **kargs):
"""Creates a new Logical Formula
LF(fol) -> lf
The first parameter must be the source to be used to generate the LF.
If it is a FOL, you can specify the argument 'header' to eliminate the header if it is there
"""
if len(args) > 0:
header = kargs.get('header', None)
fol = copy(args[0])
if isinstance(fol, str):
fol = FOL(fol)
if header and args[0].info[0] == header:
fol.info = fol.info[-1]
# print "*"
# print ">", header, fol
try:
# print '\n-', fol
logger.debug('FOL: %s', fol)
fol.convert2PrenexForm()
logger.debug('PRENEX FOL: %s', fol)
# print '*', fol
fol.skolemize()
logger.debug('SKOLEMIZED FOL: %s', fol)
fol.push_operand(FOL.OR)
self.info = fol.info
logger.debug('LF: %s', self)
except AttributeError as e:
raise Exception('Not a valid FOL%s' % fol)
else:
self.info = []
def test_skolemize(self):
# TODO test with for alls
in_list = [
['some', ['A'], ['and', ['b'], ['some', ['B'], ['a', ['c']]]]],
['fol', ['1'], ['some', ['A'], ['and', ['b'], ['some', ['B'], ['a', ['c']]]]]],
# some(A,and(4,all(B,a(4)))) -> all(B,and(4,a(4)))
['some', ['A'], ['and', ['b'], ['all', ['B'], ['a', ['c']]]]],
['some', ['A'], ['and', ['b'], ['all', ['B'], ['a', ['B']]]]],
]
out_list = [
['and', ['b'], ['a', ['c']]],
['and', ['b'], ['a', ['c']]],
['all', ['B'], ['and', ['b'], ['a', ['c']]]],
['all', ['B'], ['and', ['b'], ['a', ['B']]]], # TODO this b should be changed
]
for in_test, test in zip(in_list, out_list):
f = FOL()
f.info = in_test
f.skolemize()
output = f.info
assert output == test, (output, test)