tempest/CHANGELOG.md

Changelog
==============

This changelog lists only the most important changes. Smaller (bug)fixes as well as non-mature features are not part of the changelog.
The releases of major and minor versions contain an overview of changes since the last major/minor update.


Version 1.6.x
-------------
## Version 1.6.4 (20xx/xx)
- Added support for model checking LTL properties in the sparse (and dd-to-sparse) engine. Requires building with Spot or an external LTL to deterministic automaton converter (using option `--ltl2datool`).
- Added cmake options `STORM_USE_SPOT_SYSTEM` and `STORM_USE_SPOT_SHIPPED` to facilitate building Storm with [Spot](https://spot.lrde.epita.fr/).
- Improved parsing of formulas in PRISM-style syntax.
- Added export of schedulers that use memory (in particular optimizing schedulers for LTL properties)
- Added support for PRISM models that use unbounded integer variables.
- Added an export of check results to json. Use `--exportresult` in the command line interface.
- Added computation of steady state probabilities for DTMC/CTMC in the sparse engine. Use `--steadystate` in the command line interface.
- Implemented parsing and model building of Stochastic multiplayer games (SMGs) in the PRISM language. No model checking implemented (yet).
- API: Simulation of prism-models 
- API: Model-builder takes a callback function to prevent extension of particular actions, prism-to-explicit mapping can be exported
- API: Export of dice-formatted expressions
- Prism-language/explicit builder: Allow action names in commands writing to global variables if these (clearly) do not conflict with assignments of synchronizing commads.
- Prism-language: n-ary predicates are supported (e.g., ExactlyOneOf)
- Added support for continuous integration with Github Actions.
- `storm-pars`: Exploit monotonicity for computing extremal values and parameter space partitioning.

## Version 1.6.3 (2020/11)
- Added support for multi-objective model checking of long-run average objectives including mixtures with other kinds of objectives.
- Added support for generating optimal schedulers for globally formulae.
- Simulator supports exact arithmetic.
- Added switch `--no-simplify` to disable simplification of PRISM programs (which sometimes costs a bit of time on extremely large inputs).
- Fixed issues with JANI inputs concerning .
    - transient variable expressions in properties,
    - constants in properties, and
    - integer variables with either only an upper or only a lower bound.
- `storm-pomdp`: States can be labelled with values for observable predicates.
- `storm-pomdp`: (Only API) Track state estimates.
- `storm-pomdp`: (Only API) Reduce computation of state estimates to computation on unrolled MDP.

## Version 1.6.2 (2020/09)
- Prism program simplification improved.
- Revamped implementation of long-run-average algorithms, including scheduler export for LRA properties on Markov automata.
- Support for step-bounded properties of the form ... [F[x,y] ... ] for DTMCs and MDPs (sparse engine).
- Renamed portfolio engine to automatic 
- `storm-dft`: Fix for relevant events when using symmetry reduction.
- `storm-pomdp`: Fix for --transformsimple and --transformbinary when used with until formulae.
- `storm-pomdp`: POMDPs can be parametric as well.

## Version 1.6.0 (2020/06)
- Changed default Dd library from `cudd` to `sylvan`. The Dd library can be changed back to `cudd` using the command line switch `--ddlib`.
- Scheduler export: Properly handle models with end components. Added export in `.json` format.
- CMake: Search for Gurobi prefers new versions.
- CMake: We no longer ship xerces-c. If xerces-c is not found on the system, storm-gspn will not be able to parse xml-based GSPN formats.
- CMake: Added option `STORM_LOAD_QVBS` to automatically download the quantitative verification benchmark set.
- Eigen library: The source code of Eigen is no longer included but downloaded from an external repository instead. Incremented Eigen version to 3.3.7 which fixes a compilation issue with recent XCode versions.
- Tests: Enabled tests for permissive schedulers.
- `storm-counterexamples`: fix when computing multiple counterexamples in debug mode.
- `storm-dft`: Renamed setting `--show-dft-stats` to `dft-statistics` and added approximation information to statistics.
- `storm-pomdp`: Implemented approximation algorithms that explore (a discritization of) the belief MDP, allowing to compute safe lower- and upper bounds for a given property.
- `storm-pomdp`: Implemented almost-sure reachability computations: graph-based, one-shot SAT-based, and iterative SAT-based.
- `storm-pomdp': Various changes such that transformation to pMCs is now again supported (and improved).
- Fixed several compiler warnings.


Version 1.5.x
-------------

## Version 1.5.1 (2020/03)
- Jani models are now parsed using exact arithmetic.

## Version 1.5.0 (2020/03)
- Added portfolio engine which picks a good engine (among other settings) based on features of the symbolic input.
- Abort of Storm (via timeout or CTRL+C for example) is now gracefully handled. After an abort signal the program waits some seconds to output the result computed so far and terminates afterwards. A second signal immediately terminates the program.
- Setting `--engine dd-to-sparse --bisimulation` now triggers extracting the sparse bisimulation quotient.
- JIT model building is now invoked via `--engine jit` (instead of `--jit`).
- DRN: support import of choice labelling.
- Added option `--build:buildchoiceorig` to build a model (PRISM or JANI) with choice origins (which are exported with, e.g. `--exportscheduler`).
- Implemented optimistic value iteration for sound computations and set it as new default in `--sound` mode.
- Time bounded properties for Markov automata are now computed with relative precision. Use `--absolute` for the previous behavior.
- Apply the maximum progress assumption while building a Markov automaton with one of the symbolic engines.
- Added option `--build:nomaxprog` to disable applying the maximum progress assumption during model building (for Markov Automata).
- Added hybrid engine for Markov Automata.
- Improved performance of the Unif+ algorithm (used for time-bounded properties on Markov Automata).
- Various performance improvements for model building with the sparse engine.
- `storm-dft`: Symmetry reduction is now enabled by default and can be disabled via `--nosymmetryreduction`.
- `storm-pomdp`: Only accept POMDPs that are canonical.
- `storm-pomdp`: Prism language extended with observable expressions.
- `storm-pomdp`: Various fixes that prevented usage.
- Several bug fixes.


Version 1.4.x
-------------

### Version 1.4.1 (2019/12)
- Implemented long run average (LRA) computation for DTMCs/CTMCs via value iteration and via gain/bias equations.
- Added several LRA related settings in a new settings module. Note that `--minmax:lramethod` has been replaced by `--lra:nondetmethod`.

### Version 1.4.0 (2019/11)
- Added support for multi-dimensional quantile queries.
- Added support for multi-objective model checking under pure (deterministic) schedulers with bounded memory using `--purescheds`.
- Allow to quickly check a benchmark from the [Quantitative Verification Benchmark Set](http://qcomp.org/benchmarks/) using the `--qvbs` option.
- Added script `resources/examples/download_qvbs.sh` to download the QVBS.
- If an option is unknown, Storm now suggests similar option names.
- Flagged several options as 'advanced' to clean up the `--help`-message. Use `--help all` to display a complete list of options.
- Support for parsing of exact time bounds for properties, e.g., `P=? [F=27 "goal"]`.
- Export of optimal schedulers when checking MDPs with the sparse engine (experimental). Use  `--exportscheduler <filename>`.
- PRISM language: Support for the new `round` operator.