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modify my code such that the truth table algorithm can work with the general knowledge base like for example this TELL ( a < =

modify my code such that the truth table algorithm can work with the general knowledge base like for example this
TELL
(a <=>(c => ~d)) & b & (b => a); c; ~f || g;
ASK
~d & (~g => ~f)
import re
import itertools
# Function to replace logical operators
def replace_operators(expr):
# Replace biconditional operators
expr = re.sub(r'(\w+)\s*<=>\s*(\w+)', r'((\1 and \2) or (not \1 and not \2))', expr)
# Replace implications
expr = re.sub(r'(\w+)\s*=>\s*(\w+)', r'(not \1 or \2)', expr)
return expr
# Function to preprocess logical expressions
def preprocess_expression(expr):
expr = replace_operators(expr)
expr = expr.replace('~',' not ')
expr = expr.replace('&',' and ')
expr = expr.replace('||',' or ')
return expr
# Function to evaluate logical expressions
def eval_expression(preprocessed_expr, truth_assignment):
try:
# Ensure all variables are present in the truth assignment
for var in re.findall(r'\b\w+\b', preprocessed_expr):
if var not in truth_assignment:
truth_assignment[var]= False
return eval(preprocessed_expr, {"__builtins__": None}, truth_assignment)
except Exception as e:
print(f"Error evaluating expression '{preprocessed_expr}': {e}")
return False
# Function to parse propositions from the knowledge base and query separately
def parse_propositions(expr):
return set(re.findall(r'\b\w+\b', expr))
# Truth Table Enumeration algorithm
def tt_entails(kb, alpha):
kb_props = list(parse_propositions(kb))
alpha_props = list(parse_propositions(alpha))
all_props = list(set(kb_props + alpha_props))
print("Propositions:", all_props)
return tt_check_all(kb, alpha, all_props, {})
def tt_check_all(kb, alpha, symbols, model):
if not symbols:
if pl_true(kb, model):
return pl_true(alpha, model)
else:
return True
else:
p, rest = symbols[0], symbols[1:]
return (tt_check_all(kb, alpha, rest, extend(model, p, True)) and
tt_check_all(kb, alpha, rest, extend(model, p, False)))
def extend(model, p, value):
new_model = model.copy()
new_model[p]= value
return new_model
def pl_true(kb, model):
clauses =[clause.strip() for clause in kb.split(';') if clause.strip()]
#print("Evaluating KB with model:", model)
for clause in clauses:
preprocessed_clause = preprocess_expression(clause)
if not eval_expression(preprocessed_clause, model):
#print(f"Clause '{clause}' is false in model {model}")
return False
#print("KB is true in model", model)
return True
# Modified TT algorithm to count the models
def tt_entails_with_count(kb, alpha):
kb_props = list(parse_propositions(kb))
alpha_props = list(parse_propositions(alpha))
all_props = list(set(kb_props + alpha_props))
num_models =0
num_valid_models =0
for values in itertools.product([True, False], repeat=len(kb_props)):
model = dict(zip(kb_props, values))
#print("Evaluating model:", model)
kb_true = pl_true(kb, model)
#print("KB is", "true" if kb_true else "false", "for model:", model)
if kb_true:
num_models +=1
alpha_true = eval_expression(preprocess_expression(alpha), model)
#print("Query is", "true" if alpha_true else "false", "for model:", model)
if alpha_true:
num_valid_models +=1
#print(f"Final count of valid models: {num_valid_models} out of {num_models} models evaluated.")
return "YES" if num_valid_models >0 else "NO", num_valid_models
# Forward Chaining algorithm using PL-FC-Entails pseudocode
def forward_chaining(kb, query):
clauses =[clause.strip() for clause in kb.split(';') if clause.strip()]
agenda =[]
inferred ={}
count ={}
# Initialize agenda, inferred, and count
for clause in clauses:
if '=>' in clause:
premises, conclusion = clause.split('=>',1)
premises = premises.strip().split('&')
conclusion = conclusion.strip()
count[clause]= len(premises)
for p in premises:
if p not in inferred:
inferred[p]= False
if p not in agenda:
agenda.append(p)
if conclusion not in inferred:
inferred[conclusion]= False
else:
if clause not in inferred:
inferred[clause]= False
if clause not in agenda:
agenda.append(clause)
# Process the agenda
while agenda:
p = agenda.pop(0)
if not inferred[p]:
inferred[p]= True
for clause in clauses:
if p in clause and '=>' in clause:
premises, c

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