v0.2.4

SV-COMP 2024 version

v0.2.2

SV-COMP 2022 version.

v0.2.3

SV-COMP 2023 version

v0.2.1

SV-COMP 2021 version.

v0.1.25

SVCOMP 2020 version.

v0.1.24

SVCOMP 2019 version.

v0.1.23

Note: I did not finish the release notes, but this version is the one used in SV-COMP18 and should therefore be used as the current version.

v0.1.22

Bugfixes

• various bugfixes and improvements to VpDomain (see #239)
• various bugfixes and improvements to TreeAutomizer
• fixed a bug in non-relational domains concerning COMPNEQ by rewriting expressions. When in an expression expr = expr1 != expr2 the COMPNEQ operator is encountered, the expression is rewritten to expr = expr1 == !expr2 in all abstract domains (if dealing with boolean results).
• re-fixed another bug in non-relational domains evaluators.

Plumbing

• improved performance of Hopcroft tree minimization by working only on partitions instead of also holding a relation
• updated SMTInterpol to 2.1-404-g5f835ca

Known Issues

• README and Website usage instructions outdated (see #135)
• Startup with generated binary ./Ultimate stalls if no X display is available

v0.1.21

Features

• new equality domain (VPDomain) that uses weak equivalences and congruence closures (see #159, #224, #162)
• InvariantSynthesis now supports algorithm that guesses danger invariants
• support for reading Floyd-Hoare automata from files
• preliminary support for reuse of Floyd-Hoare automata (regression verification)
• now using cell precision for arrays in fault localization
• new auotmaton operation Relabel: Relabel replaces the labels of all states with numbers. If several operations are executed in a row the names of the states can become very long (and cause OOMs). This operation will give you shorter strings.
• options for output of statistics as .csv file during normal runs (closes #190)
• preliminary version of random tree automata generator
• Ultimate version now also contains the git hash and a modifier if the repository is dirty; the version is printed in CLI and GUI frontends
• IRD quantifier elimination now uses anti-DER rule

NCSB complementation of (non-deterministic) Büchi automata:

• integrated new NCSB implementations
• add support for LazyS optimization to NCSB implementation
• use new NCSB algorithms in RefineBuchi
• LazyS optimization for original BuchiComplementNCSB operation
• BuchiDifference for simple and lazy NCSB

Bugfixes

• various bugfixes for TreeAutomizer (see #210, #143)
• fixed bug that lead to a crash when interpreting an .ats file with a TreeAutomaton that contained unused symbols in its alphabet
• fixed a bug in CrossProducts.binarySelective(...)
• fixed a bug in ThreeValuedEquivalenceRelation (see #234)
• various fixes to ElimStorePlain
• fix nontermination by not computing differences if abstraction is already empty
• fix bug in AffineTerm: omit zero in RHS if you bring variable to RHS
• fix bug in fixpoint check for lassos with auxvars (closes #220)
• various bugfixes and improvements to different loop acceleration modes
• fix script dumping for SpaceExParser
• fixed a bug during prelog generation by explicitly specifying the classloader to prevent failures under different classloaders (e.g., during maven or inside tomcat)
• fixed NPE in backtranslation (if there is no C function, use the boogie name instead of crashing) (closes #215)
• fixed a bug in nonrelational domains of abstract interpretation where renameVariables() did not rename variables.

Plumbing

Utilities

• optimization of UnionFind.union(...) -- should run in amortized logarithmic time
• updated ThreeValuedEquivalenceRelation s.t. it can detect contradictions now
• reworked CongruenceClosure implementation
• UnionFind now takes a comparator as parameter and ensures that representatives are always minimal elements in their equivalence class with respect to the given comparator
• add auxiliary method that computes the "guarded havoc"
• merged utility classes SetOperations and DataStructureUtils, using the intersection implementation of DataStructureUtils (~20% faster)

Conventions and naming

• constants of auxVars get the c_aux_ prefix
• renamed UltimateCore to de.uni_freiburg.informatik.ultimate.core
• renamed TraceChecker to TraceCheck (closes #229)

SMT and "Ultimate normal form"

• now using Rational instead of BigInteger and BigDecimal in many places (should be the default way of representing constants)
• now using negated equality instead of "distinct" in Term
• added various checks that new terms are in Ultimate normal form
• now using SmtUtils instead of Util in all places
• new methods for simplification of and/or
• `´SmtUtils`` now has a flag that controls extended location simplifications (combating useless simplifications)
• new feature for SimplifyDDA: Allow to simplify a term with respect to a given context.
• add method that can transform SMT-Terms given as strings into our Term data structure (very useful for unit tests)
• extend util function for equalities by a simplification that eliminates self-updates of arrays

CEGAR and refinement engine

• refactored CEGAR loop
• use refinement engine for the non-Büchi refinements in termination analysis
• refinement strategies can now specify their own interpolant acceptance threshold (closes #226)

Abstract interpretation

• removed IBoogieVar, add getSort() to IProgramVarOrConst, removed VARDECL from abstract interpretation (closes #222)
• add renameVariable to IAbstractState and implement it for most domains except SMTTheory and VpDomain
• add IAbstractState.evaluate(...) and pretty inefficient default implementation
• add methods to IAbstractDomain that will be called before and after fixpoint computation
• more precise calculations in nonrelational domains of abstract interpretation

Misc

• CACSL2BoogieTranslatorObserver now tolerates other models
• TimeoutResults now display long descriptions
• add BoogieModSetAnnotator to test dependencies
• move CDTDecorator to CDTParser (required for multiparse, see #37, #38)
• add option that hides backtranslation warnings in BoogiePreprocessor
• change build properties s.t. all projects use workspace build properties
• add new library as dependency of Library-Automata: trove 3.0.3
• updated SMTInterpol to 2.1-397-g31e711a0

Known Issues

• README and Website usage instructions outdated (see #135)
• Startup with generated binary ./Ultimate stalls if no X display is available
• The SMTInterpol version used in this release contains some unsoundness bugs

v0.1.20

Features

Change of default settings

• logic for auxiliary solver becomes ALL
• do not bring TransFormulas in CNF
• ICFG does partial skolemization by default

Misc

• support for computation of danger invariants in InvariantSynthesis plugin
• optimization for auxiliary bitvector equality method
• added entry and exit functions to violation witnesses (closes #113)
• improve assertion order modulation in strategies that use them by counting already analyzed path programs and saving/logging trace hashes for debugging (closes #204)
• new abstract interpretation domain SMTTheoryDomain - a domain based on predicate transformer and SMT solver calls.

Solver update

• Now using MathSat5 nightly build 84cb666a6c83 (Jul 12 2017)

Bugfixes

• various bugfixes, e.g. in TermVariableRenamer and LassoRankerStarter, renaming of variables to constants in some SMT operations,
• fix backtranslation bug: if a procedure without implementation is called, replace the call/return with an fcall and avoid return statement shifting workaround; for C programs without explicit return, remove assertion (closes #205)
• add support for expressions containing variables with array type in BoogiePreprocessor backtranslator and fix a bug where struct types where not treated as intended
• fix bug in IcfgTransformer that lead to new return transitions being created before the corresponding call transition was created (closes #207)
• fix IndexOutOfBounds exception in backtranslation (closes #209)
• fix not considering AutomataScriptInterpreterOverallResult in overall result message (closes #6)
• bugfix SSD quantifier elimination
• fix Overapprox annotation being unmergeable (closes #189)
• fix bug that lead to different .csv files during testing by using AbstractCegarLoop.Result in CodeCheck instead of redefining own enum (closes #200)

Plumbing

• new data structure for an equivalence relation with a ternary membership status (equal, not equal, unknown)
• use actual hierachical prestate in AbstractInterpretation soundness check instead of stateafterleaving
• use monteverdi nexus oss repository proxy to prevent build breakage due to high load on eclipse p2 repositories
• introduced IRankedLetter interface: every letter in a TreeAutomaton's alphabet now needs to have an explicit rank;
• moved helper files for TreeAutomizer from modelcheckerutils/hornutil to its own library Library-TreeAutomizer
• add new auxiliary method (distinct) to SmtUtils

Known Issues

• README and Website usage instructions outdated (see #135)
• Startup with generated binary ./Ultimate stalls if no X display is available