prism-converter: Add README

# Prism converter

This directory containers a helper program called `prism-converter` that

converts transition matrices of PRISM[1] models into coalgebra specifications.

## Building

```sh

stack build --flag copar:benchmark-generators

```

## Generating transition matrices

You can generate those transition matrices with PRISM itself by using:

```sh

prism -exporttrans TRA_FILE -exportstates STA_FILE -const CONST_ASSIGNMENTS

```

Given the constant assignments `CONST_ASSIGNMENTS` (see the PRISM documentation

on syntax and semantics of those), thsi output a transition matrix in `TRA_FILE`

and a states file in `STA_FILE`. Please see [2] for additional details.

## Converting them into coalgebra specs

The resulting files can then be converted into a coalgebra specification using

```sh

stack exec prism-converter -- --model-type TYPE --states-file STA_FILE TRA_FILE

```

where type is one of dtmc, ctmc or mdp.

See `stack exec prism-converter -- --help` for details.

[1]: https://www.prismmodelchecker.org

[2]: https://www.prismmodelchecker.org/manual/RunningPRISM/ExportingTheModel