def composition(goals: Set[Goal],
name: str = None,
description: str = None) -> Goal:
if name is None:
names = []
for goal in goals:
names.append(goal.name)
names.sort()
conj_name = ""
for name in names:
conj_name += name + "||"
name = conj_name[:-2]
set_of_contracts = set()
new_goal_world = None
for g in goals:
set_of_contracts.add(g.specification)
if g.world is not None:
if new_goal_world is None:
new_goal_world = g.world
else:
if new_goal_world is not g.world:
raise GoalException(
"conjoining goals that have different 'variables'")
try:
new_contract = Contract.composition(set_of_contracts)
except IncompatibleContracts as e:
raise GoalAlgebraOperationFail(
goals=goals,
operation=GoalFailOperations.composition,
contr_ex=e)
except InconsistentContracts as e:
raise GoalAlgebraOperationFail(
goals=goals,
operation=GoalFailOperations.composition,
contr_ex=e)
except UnfeasibleContracts as e:
raise GoalAlgebraOperationFail(
goals=goals,
operation=GoalFailOperations.composition,
contr_ex=e)
new_goal = Goal(name=name,
description=description,
specification=new_contract,
world=new_goal_world)
return new_goal
from world.simple_gridworld import SimpleGridWorld, SeA, SeB, GoA, GoB
sw = SimpleGridWorld()
t = sw.typeset
"""We are using the Init pattern which is basically atom corresponding to the type at time zero,
e.g. type: a => atom: a"""
c1 = Contract(assumptions=Init(t["se_a"]), guarantees=Init(t["a"]))
print(c1)
c2 = Contract(assumptions=Init(t["se_b"]), guarantees=Init(t["b"]))
print(c2)
try:
c12 = Contract.composition({c1, c2})
print(c12)
except ContractException as e:
print(e.message)
print("Unsatisfiable because se_a and se_b are mutually exclusive")
"""We can compute the conjunction"""
try:
c12 = Contract.conjunction({c1, c2})
print(c12)
print("Conjunction is OK")
except ContractException as e:
print(e.message)
"""Let's change the assumptions to be not mutually exclusive"""
