Files
reactics/smtcheckerrsc.py
Artur Meski 781777ac56 Production of the maximal concentration
When multiple reactions are enabled, we produce the maximal concentration by exploiting the fact that reactions are sorted (increasing order).  We build the encoding starting from the inner-most reaction (with the lowest concentration level), and then build around that reaction encoding for the reactions with higher concentration levels. This allows us to avoid the disjunctions of possible resulting concentractions. E.g. (x==1 v x==3 v x==7), while we should have only x==7.
2016-03-10 12:33:32 +01:00

470 lines
18 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
from itertools import chain
import resource
from colour import *
# def simplify(x):
# return x
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()
self.verification_time = None
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_nonzero_assertion(self, level):
"""Encodes assertions that (some) variables need to be >0
We do not need to actually control all the variables,
only those that can possibly go below 0.
"""
enc_nz = True
for v in self.v[level]:
enc_nz = simplify(And(enc_nz, v >= 0))
return enc_nz
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 = []
if prod_entity in self.rs.get_reactions_by_product():
rcts_for_prod_entity = self.rs.get_reactions_by_product()[prod_entity]
meta_reactions = []
if prod_entity in self.rs.meta_reactions:
meta_reactions = self.rs.meta_reactions[prod_entity]
permanency_inhibition = None
if prod_entity in self.rs.permanent_entities:
permanency_inhibition = self.rs.permanent_entities[prod_entity]
if rcts_for_prod_entity == [] and meta_reactions == []:
return simplify(self.v[level+1][prod_entity] == 0) # this should never happen
enc_enabledness = False
# ----------- ordinary reactions --------------------------------------------
enc_rct_prod = False
for reactants,inhibitors,products in rcts_for_prod_entity:
enc_reactants = True
for reactant,concentration in reactants:
enc_reactants = simplify(And(enc_reactants,
Or(self.v[level][reactant] >= concentration, self.v_ctx[level][reactant] >= concentration)))
enc_inhibitors = True
for inhibitor,concentration in inhibitors:
enc_inhibitors = simplify(And(enc_inhibitors,
And(self.v[level][inhibitor] < concentration, self.v_ctx[level][inhibitor] < concentration)))
enc_rct_enabled = And(enc_reactants, enc_inhibitors)
enc_products = self.v[level+1][products[0][0]] == products[0][1]
enc_rct_prod = simplify(If(enc_rct_enabled, enc_products, enc_rct_prod))
enc_enabledness = simplify(Or(enc_enabledness, enc_rct_enabled))
# 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_enabledness = simplify(Or(enc_enabledness, And(enc_reactants, enc_inhibitors)))
# enc_rct_prod = simplify(Or(enc_rct_prod, And(enc_reactants, enc_inhibitors, enc_products)))
# -------- meta reactions ---------------------------------------------------
for r_type,command_entity,reactants,inhibitors in meta_reactions:
# command entity is e.g. 'inc' for incrementation operation
# (inc,W) gives us the value W by which the given entity's value should be incremented
enc_reactants = True
enc_inhibitors = True
for reactant,concentration in reactants:
enc_reactants = simplify(And(enc_reactants,
Or(self.v[level][reactant] >= concentration, self.v_ctx[level][reactant] >= concentration)))
# command entity needs to be present (with concentration level > 0) in order to perform the operation
enc_reactants = simplify(And(enc_reactants,
Or(self.v[level][command_entity] > 0, self.v_ctx[level][command_entity] > 0)))
for inhibitor,concentration in inhibitors:
enc_inhibitors = simplify(And(enc_inhibitors,
And(self.v[level][inhibitor] < concentration, self.v_ctx[level][inhibitor] < concentration)))
if r_type == "inc":
value_after_inc = If(self.v[level][prod_entity]>self.v_ctx[level][prod_entity],self.v[level][prod_entity],self.v_ctx[level][prod_entity]) + \
If(self.v[level][command_entity]>self.v_ctx[level][command_entity],self.v[level][command_entity],self.v_ctx[level][command_entity])
enc_products = self.v[level+1][prod_entity] == value_after_inc
elif r_type == "dec":
value_after_dec = simplify(If(self.v[level][prod_entity]>self.v_ctx[level][prod_entity],self.v[level][prod_entity],self.v_ctx[level][prod_entity]) - \
If(self.v[level][command_entity]>self.v_ctx[level][command_entity],self.v[level][command_entity],self.v_ctx[level][command_entity]))
enc_products = self.v[level+1][prod_entity] == If(value_after_dec < 0, 0, value_after_dec)
else:
raise RuntimeError("Unknown meta-reaction type: " + repr(r_type))
enc_enabledness = simplify(Or(enc_enabledness, And(enc_reactants, enc_inhibitors)))
enc_rct_prod = simplify(Or(enc_rct_prod, And(enc_reactants, enc_inhibitors, enc_products)))
# -----------------------------------------------------------------------------
if not permanency_inhibition == None:
enc_reactants = Or(self.v[level][prod_entity] >= concentration, self.v_ctx[level][prod_entity] >= concentration)
enc_inhibitors = True
for inhibitor,concentration in permanency_inhibition:
enc_inhibitors = simplify(And(enc_inhibitors,
And(self.v[level][inhibitor] < concentration, self.v_ctx[level][inhibitor] < concentration)))
enc_products = simplify(self.v[level+1][prod_entity] == \
If(self.v[level][prod_entity] > self.v_ctx[level][prod_entity],self.v[level][prod_entity],self.v_ctx[level][prod_entity]))
enc_enabledness = simplify(Or(enc_enabledness, And(enc_reactants, enc_inhibitors)))
enc_permanency = And(enc_reactants, enc_inhibitors, enc_products)
enc_rct_prod = simplify(Or(enc_rct_prod, enc_permanency))
# -----------------------------------------------------------------------------
enc_when_to_produce_zero_conc = simplify(And(Not(enc_enabledness), self.v[level+1][prod_entity] == 0))
enc_rct_prod = Or(enc_rct_prod, enc_when_to_produce_zero_conc)
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 = set(range(len(self.rs.background_set)))
enc_trans = True
reactions = self.rs.get_reactions_by_product()
meta_reactions = self.rs.meta_reactions
for prod_entity in chain(reactions, meta_reactions):
unused_entities.discard(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"""
raise RuntimeError("Should not be used with RSC")
# 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 enc_state_with_blocking(self, level, prop):
"""Encodes the state at the given level with blocking certain concentrations"""
required,blocked = prop
enc = True
for ent,conc in required:
e_id = self.rs.get_entity_id(ent)
enc = And(enc, self.v[level][e_id] >= conc)
for ent,conc in blocked:
e_id = self.rs.get_entity_id(ent)
enc = And(enc, self.v[level][e_id] < conc)
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{: >70}".format("[ 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, print_witness=True,
print_time=True, print_mem=True, max_level=100):
"""Main testing function"""
if print_time:
# start = time()
start = resource.getrusage(resource.RUSAGE_SELF).ru_utime
self.prepare_all_variables()
self.solver.add(self.enc_init_state(0))
current_level = 0
self.prepare_all_variables()
# self.solver.add(self.enc_nonzero_assertion(0))
while True:
self.prepare_all_variables()
# self.solver.add(self.enc_nonzero_assertion(current_level+1))
print("\n{:-^70}".format("[ Working at level=" + str(current_level) + " ]"))
stdout.flush()
# reachability test:
print("[" + colour_str(C_BOLD, "i") + "] Adding the reachability test...")
self.solver.push()
self.solver.add(self.enc_state_with_blocking(current_level,state))
result = self.solver.check()
if result == sat:
print("[" + colour_str(C_BOLD, "+") + "] " + colour_str(C_GREEN, "SAT at level=" + str(current_level)))
if print_witness:
print("\n{:=^70}".format("[ WITNESS ]"))
self.decode_witness(current_level)
break
else:
self.solver.pop()
print("[" + colour_str(C_BOLD, "i") + "] Unrolling the transition relation")
self.solver.add(self.enc_transition_relation(current_level))
print("{:->70}".format("[ 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()
stop = resource.getrusage(resource.RUSAGE_SELF).ru_utime
self.verification_time = stop-start
print()
print("\n[i] {: >60}".format(" Time: " + repr(self.verification_time) + " s"))
if print_mem:
print("[i] {: >60}".format(" Memory: " + repr(resource.getrusage(resource.RUSAGE_SELF).ru_maxrss/(1024*1024)) + " MB"))
def get_verification_time(self):
return self.verification_time
def show_encoding(self, state, print_witness=True,
print_time=False, print_mem=False, max_level=100):
"""Encoding debug function"""
self.prepare_all_variables()
init_s = self.enc_init_state(0)
print(init_s)
self.solver.add(init_s)
current_level = 0
self.prepare_all_variables()
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()
s = self.enc_min_state(current_level,state)
print("Test: ", s)
self.solver.add(s)
result = self.solver.check()
if result == sat:
print("\n[+] " + colour_str(C_RED, "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")
t = self.enc_transition_relation(current_level)
print(t)
self.solver.add(t)
print("-----[ level=" + str(current_level) + " done ]")
current_level += 1
if current_level > max_level:
print("Stopping at level=" + str(max_level))
break
else:
x=input("Next level? ")
x=x.lower()
if not (x == "y" or x == "yes"):
break