Exemple #1
0
        public LemmaDecl GenerateEmptyBlockLemma(Block block, IEnumerable <Block> finalCfgSuccessors, string lemmaName)
        {
            //Term cmds = new TermList(cmdIsaVisitor.Translate(block.Cmds));
            var  blockDefName = isaBlockInfo.CmdsQualifiedName(block);
            Term blockDefTerm = IsaCommonTerms.TermIdentFromName(blockDefName);
            var  cmdsReduce   = IsaBoogieTerm.RedCmdList(boogieContext, blockDefTerm, initState, finalState);
            var  assumptions  = new List <Term> {
                cmdsReduce
            };

            if (finalCfgSuccessors.Any())
            {
                assumptions.Add(LemmaHelper.ConjunctionOfSuccessorBlocks(finalCfgSuccessors, declToVCMapping, vcinst));
            }

            var conclusion = ConclusionBlock(finalCfgSuccessors, normalInitState, finalState, declToVCMapping, vcinst);

            var proof = new Proof(
                new List <string>
            {
                "using assms",
                "unfolding " + blockDefName + "_def",
                "apply cases",
                "by auto"
            }
                );

            return(new LemmaDecl(lemmaName, ContextElem.CreateWithAssumptions(assumptions), conclusion, proof));
        }
Exemple #2
0
        private static Term ConclusionBlock(
            IEnumerable <Block> b_successors,
            Term normalInitState,
            Term finalState,
            IDictionary <NamedDeclaration, Term> declToVCMapping,
            VCInstantiation <Block> vcinst,
            bool useMagicFinalState = false)
        {
            if (useMagicFinalState)
            {
                return(new TermBinary(finalState, IsaBoogieTerm.Magic(), TermBinary.BinaryOpCode.Eq));
            }

            Term nonFailureConclusion =
                new TermBinary(finalState, IsaBoogieTerm.Failure(), TermBinary.BinaryOpCode.Neq);

            var normalFinalState = IsaCommonTerms.TermIdentFromName("n_s'");

            Term ifNormalConclusionLhs = new TermBinary(finalState, IsaBoogieTerm.Normal(normalFinalState),
                                                        TermBinary.BinaryOpCode.Eq);

            Term ifNormalConclusionRhs1 = new TermBinary(normalFinalState, normalInitState, TermBinary.BinaryOpCode.Eq);

            var ifNormalConclusionRhs =
                !b_successors.Any()
                    ? ifNormalConclusionRhs1
                    : new TermBinary(
                    ifNormalConclusionRhs1,
                    LemmaHelper.ConjunctionOfSuccessorBlocks(b_successors, declToVCMapping, vcinst),
                    TermBinary.BinaryOpCode.And);

            Term ifNormalConclusion =
                new TermQuantifier(
                    TermQuantifier.QuantifierKind.ALL,
                    new List <Identifier> {
                normalFinalState.Id
            },
                    new TermBinary(
                        ifNormalConclusionLhs,
                        ifNormalConclusionRhs,
                        TermBinary.BinaryOpCode.Implies)
                    );

            return(new TermBinary(nonFailureConclusion, ifNormalConclusion, TermBinary.BinaryOpCode.And));
        }
Exemple #3
0
        public LemmaDecl GenerateCfgLemma(
            Block block,
            Block finalCfgBlock,
            bool isContainedInFinalCfg,
            IEnumerable <Block> successors,
            IEnumerable <Block> finalCfgSuccessors,
            Term cfg,
            Func <Block, string> cfgLemmaName,
            LemmaDecl BlockLemma)
        {
            var red = IsaBoogieTerm.RedCFGMulti(
                boogieContext,
                cfg,
                IsaBoogieTerm.CFGConfigNode(new NatConst(isaBlockInfo.BlockIds[block]),
                                            IsaBoogieTerm.Normal(normalInitState)),
                IsaBoogieTerm.CFGConfig(finalNode, finalState));
            var assumption = new List <Term> {
                red
            };
            var hasVcAssm = false;

            if (isContainedInFinalCfg)
            {
                assumption.Add(vcinst.GetVCObjInstantiation(finalCfgBlock, declToVCMapping));
                hasVcAssm = true;
            }
            else
            {
                //vc assumption is conjunction of reachable successors in final cfg
                if (finalCfgSuccessors.Any())
                {
                    assumption.Add(
                        LemmaHelper.ConjunctionOfSuccessorBlocks(finalCfgSuccessors, declToVCMapping, vcinst));
                    hasVcAssm = true;
                }
            }

            Term conclusion = new TermBinary(finalState, IsaBoogieTerm.Failure(), TermBinary.BinaryOpCode.Neq);

            var nodeLemma     = isaBlockInfo.BlockCmdsMembershipLemma(block);
            var outEdgesLemma = isaBlockInfo.OutEdgesMembershipLemma(block);
            var proofMethods  = new List <string>();


            var eruleLocalBlock =
                "erule " + (hasVcAssm ? ProofUtil.OF(BlockLemma.Name, "_", "assms(2)") : BlockLemma.Name);

            if (isContainedInFinalCfg && LemmaHelper.FinalStateIsMagic(block))
            {
                proofMethods.Add("apply (rule converse_rtranclpE2[OF assms(1)], fastforce)");
                proofMethods.Add(ProofUtil.Apply("rule " +
                                                 ProofUtil.OF("red_cfg_multi_backwards_step_magic", "assms(1)",
                                                              nodeLemma)));
                proofMethods.Add(ProofUtil.By(eruleLocalBlock));
                return(new LemmaDecl(cfgLemmaName(block), ContextElem.CreateWithAssumptions(assumption), conclusion,
                                     new Proof(proofMethods)));
            }

            if (successors.Any())
            {
                proofMethods.Add("apply (rule converse_rtranclpE2[OF assms(1)], fastforce)");
                var cfg_lemma = finalCfgSuccessors.Any()
                    ? "red_cfg_multi_backwards_step"
                    : "red_cfg_multi_backwards_step_2";

                proofMethods.Add(ProofUtil.Apply("rule " +
                                                 ProofUtil.OF(cfg_lemma, "assms(1)", nodeLemma)));
                proofMethods.Add(ProofUtil.Apply(eruleLocalBlock));
                proofMethods.Add("apply (" + ProofUtil.Simp(outEdgesLemma) + ")");
                foreach (var bSuc in successors)
                {
                    proofMethods.Add("apply (erule member_elim, simp)");
                    proofMethods.Add("apply (erule " + cfgLemmaName(bSuc) + ", simp?" + ")");
                }

                proofMethods.Add("by (simp add: member_rec(2))");
            }
            else
            {
                proofMethods.Add("apply (rule converse_rtranclpE2[OF assms(1)], fastforce)");
                proofMethods.Add("apply (rule " + ProofUtil.OF("red_cfg_multi_backwards_step_no_succ", "assms(1)",
                                                               nodeLemma, outEdgesLemma) + ")");
                if (isContainedInFinalCfg)
                {
                    proofMethods.Add("using " + ProofUtil.OF(BlockLemma.Name, "_", "assms(2)") + " by blast");
                }
                else
                {
                    proofMethods.Add("using " + BlockLemma.Name + " by blast");
                }
            }

            return(new LemmaDecl(cfgLemmaName(block), ContextElem.CreateWithAssumptions(assumption), conclusion,
                                 new Proof(proofMethods)));
        }