def call_method_with_known_truth_assumptions(*args, **kwargs):
if len(args) > assumptionsIndex:
args = list(args)
assumptions = args[assumptionsIndex]
assumptions = defaults.checkedAssumptions(assumptions)
assumptions += self.assumptions
args[assumptionsIndex] = defaults.checkedAssumptions(assumptions)
else:
assumptions = kwargs.get('assumptions', USE_DEFAULTS)
assumptions = defaults.checkedAssumptions(assumptions)
assumptions = tuple(assumptions) + self.assumptions
kwargs['assumptions'] = defaults.checkedAssumptions(assumptions)
return attr.__call__(*args, **kwargs)
def __init__(self, implicationExpr, assumptions=None):
from proveit.logic import Implies
assumptions = defaults.checkedAssumptions(assumptions)
prev_default_assumptions = defaults.assumptions
defaults.assumptions = assumptions # these assumptions will be used for deriving any side-effects
try:
# obtain the implication and antecedent KnownTruths
assert isinstance(implicationExpr, Implies) and len(implicationExpr.operands)==2, 'The implication of a modus ponens proof must refer to an Implies expression with two operands'
try:
# Must prove the implication under the given assumptions.
# (if WILDCARD_ASSUMPTIONS is included, it will be proven by assumption if there isn't an existing proof otherwise)
implicationTruth = implicationExpr.prove(assumptions)
_appendExtraAssumptions(assumptions, implicationTruth)
except:
raise ModusPonensFailure(implicationExpr.operands[1], assumptions, 'Implication, %s, is not proven'%str(implicationExpr))
try:
# Must prove the antecedent under the given assumptions.
# (if WILDCARD_ASSUMPTIONS is included, it will be proven by assumption if there isn't an existing proof otherwise)
antecedentTruth = implicationExpr.operands[0].prove(assumptions)
_appendExtraAssumptions(assumptions, antecedentTruth)
except:
raise ModusPonensFailure(implicationExpr.operands[1], assumptions, 'Antecedent of %s is not proven'%str(implicationExpr))
# remove any unnecessary assumptions (but keep the order that was provided)
assumptionsSet = implicationTruth.assumptionsSet | antecedentTruth.assumptionsSet
assumptions = [assumption for assumption in assumptions if assumption in assumptionsSet]
# we have what we need; set up the ModusPonens Proof
consequentTruth = KnownTruth(implicationExpr.operands[1], assumptions, self)
_checkImplication(implicationTruth.expr, antecedentTruth.expr, consequentTruth.expr)
self.implicationTruth = implicationTruth
self.antecedentTruth = antecedentTruth
Proof.__init__(self, consequentTruth, [self.implicationTruth, self.antecedentTruth])
finally:
# restore the original default assumptions
defaults.assumptions = prev_default_assumptions
def __init__(self, expr, assumptions=None):
assumptions = defaults.checkedAssumptions(assumptions)
if expr not in assumptions:
# an Assumption proof must assume itself; that's what it does.
assumptions = assumptions + (expr,)
prev_default_assumptions = defaults.assumptions
defaults.assumptions = assumptions # these assumptions will be used for deriving any side-effects
try:
Proof.__init__(self, KnownTruth(expr, {expr}, self), [])
finally:
# restore the original default assumptions
defaults.assumptions = prev_default_assumptions
Assumption.allAssumptions[(expr, assumptions)] = self
def specialize(self, specializeMap=None, relabelMap=None, assumptions=USE_DEFAULTS):
'''
Performs a specialize derivation step to be proven under the given
assumptions, in addition to the assumptions of the KnownTruth.
This will eliminate one or more nested Forall operations, specializing
the instance variables according to specializeMap. Eliminates
the number of Forall operations required to utilize all of the
specializeMap keys. The default mapping of all instance variables
is a mapping to itself (e.g., {x:x, y:y}). Simultaneously, variables
may be relabeled via relabelMap (see the relabel method). Note, there
is a difference between making substitutons simultaneously versus
in-series. For example, the {x:y, y:x} mapping will swap x and y
variables, but mapping {x:y} then {y:x} in series would set both
variables to x.
Returns the proven specialized KnownTruth, or throws an exception if the
proof fails.
'''
from proveit import Operation, Variable, Lambda, singleOrCompositeExpression
from proveit.logic import Forall
from proof import Specialization, SpecializationFailure, ProofFailure
if not self.isUsable():
# If this KnownTruth is not usable, see if there is an alternate under the
# set of assumptions that is usable.
try:
alternate = self.expr.prove(assumptions, automation=False)
except ProofFailure:
self.raiseUnusableProof()
return alternate.specialize(specializeMap, relabelMap, assumptions)
# if no specializeMap is provided, specialize a single Forall with default mappings (mapping instance variables to themselves)
if specializeMap is None: specializeMap = dict()
if relabelMap is None: relabelMap = dict()
# Include the KnownTruth assumptions along with any provided assumptions
assumptions = defaults.checkedAssumptions(assumptions)
assumptions += self.assumptions
# For any entrys in the subMap with Operation keys, convert
# them to corresponding operator keys with Lambda substitutions.
# For example f(x,y):g(x,y) would become f:[(x,y) -> g(x,y)].
# Convert to composite expressions as needed (via singleOrCompositeExpression).
processedSubMap = dict()
for key, sub in specializeMap.iteritems():
sub = singleOrCompositeExpression(sub)
if isinstance(key, Operation):
operation = key
subVar = operation.operator
sub = Lambda(operation.operands, sub)
processedSubMap[subVar] = sub
elif isinstance(key, Variable):
processedSubMap[key] = sub
else:
raise SpecializationFailure(None, assumptions, 'Expecting specializeMap keys to be Variables, MultiVariables, or Operations with Variable/MultiVariable operators; not %s'%str(key.__class__))
remainingSubVars = set(processedSubMap.keys())
# Determine the number of Forall eliminations. There must be at least
# one (if zero is desired, relabel should be called instead).
# The number is determined by the instance variables that occur as keys
# in the subMap.
expr = self.expr
numForallEliminations = 0
while numForallEliminations==0 or len(remainingSubVars) > 0:
numForallEliminations += 1
if not isinstance(expr, Forall):
raise SpecializationFailure(None, assumptions, 'May only specialize instance variables of directly nested Forall operations')
lambdaExpr = expr.operand
assert isinstance(lambdaExpr, Lambda), "Forall Operation operand must be a Lambda function"
instanceVars, expr, conditions = lambdaExpr.parameterVars, lambdaExpr.body, lambdaExpr.conditions
for iVar in instanceVars:
if iVar in remainingSubVars:
# remove this instance variable from the remaining substitution variables
remainingSubVars.remove(iVar)
elif iVar not in processedSubMap:
# default is to map instance variables to themselves
processedSubMap[iVar] = iVar
return self._checkedTruth(Specialization(self, numForallEliminations=numForallEliminations, specializeMap=processedSubMap, relabelMap=relabelMap, assumptions=assumptions))
def __init__(self, generalTruth, numForallEliminations, specializeMap=None, relabelMap=None, assumptions=USE_DEFAULTS):
'''
Create the Specialization proof step that specializes the given general expression
using the substitution map (subMap) under the given assumptions.
Eliminates the number of nested Forall operations as indicated, substituting
their instance variables according to subMap. The default for any unspecified instance
variable is to specialize it to itself, or, in the case of a bundled variable
(Etcetera-wrapped MultiVariables), the default is to specialize it to an empty list.
Substitution of variables that are not instance variables of the Forall operations
being eliminated are to be relabeled. Relabeling is limited to substituting
a Variable to another Variable or substituting a bundled variable to
another bundled variable or list of variables (bundled or not).
'''
assumptions = list(defaults.checkedAssumptions(assumptions))
prev_default_assumptions = defaults.assumptions
defaults.assumptions = assumptions # these assumptions will be used for deriving any side-effects
try:
if relabelMap is None: relabelMap = dict()
if specializeMap is None: specializeMap = dict()
Failure = SpecializationFailure if numForallEliminations>0 else RelabelingFailure
if not isinstance(generalTruth, KnownTruth):
raise Failure(None, [], 'May only specialize/relabel a KnownTruth')
if generalTruth.proof() is None:
raise UnusableProof(KnownTruth.theoremBeingProven, generalTruth)
if not generalTruth.assumptionsSet.issubset(assumptions):
if '*' in assumptions:
# if WILDCARD_ASSUMPTIONS is included, add any extra assumptions that are needed
_appendExtraAssumptions(assumptions, generalTruth)
else:
raise Failure(None, [], 'Assumptions do not include the assumptions required by generalTruth')
generalExpr = generalTruth.expr
# perform the appropriate substitution/relabeling
specializedExpr, requirements, mappedVarLists, mappings = Specialization._specialized_expr(generalExpr, numForallEliminations, specializeMap, relabelMap, assumptions)
# obtain the KnownTruths for the substituted conditions
requirementTruths = []
requirementTruthSet = set() # avoid repeats of requirements
for requirementExpr in requirements:
try:
# each substituted condition must be proven under the assumptions
# (if WILDCARD_ASSUMPTIONS is included, it will be proven by assumption if there isn't an existing proof otherwise)
requirementTruth = requirementExpr.prove(assumptions)
if requirementTruth not in requirementTruthSet:
requirementTruths.append(requirementTruth)
requirementTruthSet.add(requirementTruth)
_appendExtraAssumptions(assumptions, requirementTruth)
except:
raise Failure(specializedExpr, assumptions, 'Unmet specialization requirement: ' + str(requirementExpr))
# remove any unnecessary assumptions (but keep the order that was provided)
assumptionsSet = generalTruth.assumptionsSet
for requirementTruth in requirementTruths:
assumptionsSet |= requirementTruth.assumptionsSet
assumptions = [assumption for assumption in assumptions if assumption in assumptionsSet]
# we have what we need; set up the Specialization Proof
self.generalTruth = generalTruth
self.requirementTruths = requirementTruths
self.mappedVarLists = mappedVarLists
self.mappings = mappings
specializedTruth = KnownTruth(specializedExpr, assumptions, self)
Proof.__init__(self, specializedTruth, [generalTruth] + requirementTruths)
finally:
# restore the original default assumptions
defaults.assumptions = prev_default_assumptions
