BoSy

BoSy is a reactive synthesis tool based on constraint-solving.

Awards

• First and second place in sequential LTL synthesis track (SYNTCOMP 2016)
• Second and third place in sequential LTL realizability track (SYNTCOMP 2016)
• First place (quality ranking) in sequential LTL synthesis track (SYNTCOMP 2017)
• Third place in sequential LTL realizability track (SYNTCOMP 2017)

Online Interface

BoSy can be tried without installation directly in your browser in our online interface.

Installation

BoSy is tested on macOS and Ubuntu.

• Requires Swift compiler
• make builds the minimal configuration:
  • downloads and builds required dependencies (in directory Tools)
  • builds the BoSy binary
• Optional dependencies are built with make all

One may need to install additional dependencies for building the tools that BoSy depends on. Check the make output and the respective tool description for more information.

System Package Dependencies

The following packages need to be installed in order to build BoSy with all dependencies.

For CAQE, you also need Rust installed.

One may also need to install the python-is-python3 package.

Ubuntu 20.04

apt-get install bison build-essential clang cmake curl flex gcc git libantlr3c-dev libbdd-dev libboost-program-options-dev libicu-dev libreadline-dev mercurial psmisc unzip vim-common wget zlib1g-dev libsqlite3-dev python3-distutils
# for rust
apt-get install rustc cargo
# Haskell stack
curl -sSL https://get.haskellstack.org/ | sh

macOS

xcode-select --install
brew tap brewsci/science
brew install libbuddy haskell-stack cmake

Usage

BoSy uses a JSON based input file format (SYNTCOMP TLSF support via a transformation tool).

Consider the following arbiter specification for two clients. Every request from a client (signal r_0/r_1) must be eventually granted (signal g_0/g_1) by the arbiter with the restriction that g_0 and g_1 may not be set simultaneously.

{
	"semantics": "mealy",
	"inputs":  ["r_0", "r_1"],
	"outputs": ["g_0", "g_1"],
	"assumptions": [],
	"guarantees": [
		"G ((!g_0) || (!g_1))",
		"G (r_0 -> (F g_0))",
		"G (r_1 -> (F g_1))"
	]
}

The command ./bosy.sh [--synthesize] arbiter.json checks the specification for realizability. If the option --synthesize is given, a solution is extracted after realizability check. Check ./bosy.sh --help for more options.

Synthesis from HyperLTL Specifications

BoSyHyper (a separate binary) supports synthesis of reactive systems from specifications given in HyperLTL.

Example

The following system keeps a secret until the publish signal arrives.

{
    "semantics": "moore",
    "inputs": ["decision", "value", "publish"],
    "outputs": ["internal", "result"],
    "assumptions": [],
    "guarantees": [
        "!internal",
        "(G (decision -> (value <-> X internal)))",
        "(G (!decision -> (internal <-> X internal)))",
        "(G ( publish -> X(internal <-> result)))"
    ],
    "hyper": [
        "forall pi1 pi2. ( (publish[pi1] || publish[pi2]) R (result[pi1] <-> result[pi2]) )"
    ]
}

$ swift run -c release BoSyHyper Samples/HyperLTL/SecretDecision.bosy
info: Linear automaton contains 4 states
info: Hyper automaton contains 1 states
info: build encoding for bound 1
info: build encoding for bound 2
info: build encoding for bound 3
realizable