Files
reactics/smtcheckerrsc.py
2016-02-19 18:19:50 +01:00

276 lines
9.3 KiB
Python

"""
SMT-based Model Checking Module for RS with Concentrations and Context Automaton
"""
from z3 import *
from time import time
from sys import stdout
class SmtCheckerRSC(object):
def __init__(self, rsca):
rsca.sanity_check()
if not rsca.is_with_concentrations():
raise RuntimeError("RS and CA with concentrations expected")
self.rs = rsca.rs
self.ca = rsca.ca
self.v = []
self.v_ctx = []
self.ca_state = []
self.next_level_to_encode = 0
self.solver = Solver()
def prepare_all_variables(self):
"""Encodes all the variables"""
self.prepare_state_variables()
self.prepare_context_variables()
self.next_level_to_encode += 1
def prepare_context_variables(self):
"""Encodes all the context variables"""
level = self.next_level_to_encode
variables = []
for entity in self.rs.background_set:
variables.append(Int("C"+str(level)+"_"+entity))
self.v_ctx.append(variables)
def prepare_state_variables(self):
"""Encodes all the state variables"""
level = self.next_level_to_encode
variables = []
for entity in self.rs.background_set:
variables.append(Int("L"+str(level)+"_"+entity))
self.v.append(variables)
self.ca_state.append(Int("CA"+str(level)+"_state"))
def enc_init_state(self, level):
"""Encodes the initial state at the given level"""
rs_init_state_enc = True
for v in self.v[level]:
rs_init_state_enc = simplify(And(rs_init_state_enc, v == 0)) # the initial concentration levels are zeroed
ca_init_state_enc = self.ca_state[level] == self.ca.get_init_state_id()
init_state_enc = simplify(And(rs_init_state_enc, ca_init_state_enc))
return init_state_enc
def enc_produced_concentration(self, level, prod_entity):
"""Encodes the produced concentrations for the given level and entity"""
rcts_for_prod_entity = self.rs.get_reactions_by_product()[prod_entity]
if rcts_for_prod_entity == []:
return simplify(self.v[level+1][prod_entity] == 0)
enc_rct_prod = False
for reactants,inhibitors,products in rcts_for_prod_entity:
enc_reactants = True
enc_inhibitors = True
# enc_products -- below
for reactant,concentration in reactants:
enc_reactants = simplify(And(enc_reactants,
Or(self.v[level][reactant] >= concentration, self.v_ctx[level][reactant] >= concentration)))
for inhibitor,concentration in inhibitors:
enc_inhibitors = simplify(And(enc_inhibitors,
And(self.v[level][inhibitor] < concentration, self.v_ctx[level][inhibitor] < concentration)))
enc_products = self.v[level+1][products[0][0]] == products[0][1]
enc_rct_prod = simplify(Or(enc_rct_prod, And(enc_reactants, enc_inhibitors, enc_products)))
return enc_rct_prod
# def enc_entity_production(self, level, prod_entity):
# """Encodes the production of a given entity from a given level at level+1"""
#
# enc_enab_cond = self.enc_enabledness(level, prod_entity)
#
# enc_ent_prod = Or(And(enc_enab_cond, self.v[level+1][prod_entity]),
# And(Not(enc_enab_cond), Not(self.v[level+1][prod_entity])))
#
# return simplify(enc_ent_prod)
def enc_transition_relation(self, level):
return simplify(And(self.enc_rs_trans(level), self.enc_automaton_trans(level)))
def enc_rs_trans(self, level):
"""Encodes the transition relation"""
unused_entities = list(range(len(self.rs.background_set)))
enc_trans = True
reactions = self.rs.get_reactions_by_product()
for prod_entity in reactions:
unused_entities.remove(prod_entity)
enc_trans = simplify(And(enc_trans, self.enc_produced_concentration(level, prod_entity)))
for prod_entity in unused_entities:
enc_trans = simplify(And(enc_trans, self.v[level+1][prod_entity] == 0))
return enc_trans
def enc_automaton_trans(self, level):
"""Encodes the transition relation for the context automaton"""
enc_trans = False
for src,ctx,dst in self.ca.transitions:
src_enc = self.ca_state[level] == src
dst_enc = self.ca_state[level+1] == dst
all_ent = set(range(len(self.rs.background_set)))
incl_ctx = set([e for e,c in ctx])
excl_ctx = all_ent - incl_ctx
ctx_enc = True
for e,c in ctx:
ctx_enc = simplify(And(ctx_enc, self.v_ctx[level][e] == c))
for e in excl_ctx:
ctx_enc = simplify(And(ctx_enc, self.v_ctx[level][e] == 0))
cur_trans = simplify(And(src_enc, ctx_enc, dst_enc))
enc_trans = simplify(Or(enc_trans, cur_trans))
return enc_trans
def enc_exact_state(self, level, state):
"""Encodes the state at the given level with the exact concentration values"""
enc = True
used_entities_ids = self.rs.get_state_ids(state)
for ent,conc in state:
e_id = self.rs.get_entity_id(ent)
enc = And(enc, self.v[level][e_id] == conc)
not_in_state = set(range(len(self.rs.background_set)))
not_in_state = not_in_state.difference(set(used_entities_ids))
for entity in not_in_state:
enc = And(enc, self.v[level][entity] == 0)
return simplify(enc)
def enc_min_state(self, level, state):
"""Encodes the state at the given level with the minimal required concentration levels"""
enc = True
for ent,conc in state:
e_id = self.rs.get_entity_id(ent)
enc = And(enc, self.v[level][e_id] >= conc)
# state_ids = self.rs.get_state_ids(state)
#
# for entity in state_ids:
# enc = And(enc, self.v[level][entity])
return simplify(enc)
def decode_witness(self, max_level, print_model=False):
m = self.solver.model()
if print_model:
print(m)
for level in range(max_level+1):
print("\n[Level=" + repr(level) + "]")
print(" State: {", end=""),
for var_id in range(len(self.v[level])):
var_rep = repr(m[self.v[level][var_id]])
if not var_rep.isdigit():
raise RuntimeError("unexpected: representation is not a positive integer")
if int(var_rep) > 0:
print(" " + self.rs.get_entity_name(var_id) + "=" + var_rep, end="")
# print(" " + repr(m[self.v[level][var_id]]), end="")
print(" }")
if level != max_level:
print(" Context set: ", end="")
print("{", end="")
for var_id in range(len(self.v[level])):
var_rep = repr(m[self.v_ctx[level][var_id]])
if not var_rep.isdigit():
raise RuntimeError("unexpected: representation is not a positive integer")
if int(var_rep) > 0:
print(" " + self.rs.get_entity_name(var_id) + "=" + var_rep, end="")
print(" }")
def check_reachability(self, state, exact_state=False, print_witness=True,
print_time=False, print_mem=False, max_level=100):
"""Main testing function"""
if print_time:
start = time()
self.prepare_all_variables()
self.solver.add(self.enc_init_state(0))
current_level = 0
self.prepare_all_variables()
print(And(self.enc_transition_relation(current_level), self.enc_init_state(0)))
while True:
self.prepare_all_variables()
print("-----[ Working at level=" + str(current_level) + " ]-----")
stdout.flush()
# reachability test:
print("[i] Adding the reachability test...")
self.solver.push()
if exact_state:
self.solver.add(self.enc_exact_state(current_level,state))
else:
self.solver.add(self.enc_min_state(current_level,state))
result = self.solver.check()
if result == sat:
print("\n[+] SAT at level=" + str(current_level))
if print_witness:
self.decode_witness(current_level)
break
else:
self.solver.pop()
print("[i] Unrolling the transition relation")
self.solver.add(self.enc_transition_relation(current_level))
print("-----[ level=" + str(current_level) + " done ]")
current_level += 1
if current_level > max_level:
print("Stopping at level=" + str(max_level))
break
if print_time:
stop = time()
print()
print("[i] Time: " + repr(stop-start))