Nichrome

Currently Nichrome supports two engines: ALPS and MLN. ALPS is an interactive synthesis engine for inductive logic programs (e.g. Datalog), and MLN is an engine for solving a system of mixed hard and soft constraints, which are widely used applications from MLNs (Markov Logic Networks) and PSLs (Probabilistic Soft Logic) areas.

Dependencies

Nichrome depends on the following environment and library:

• Java 1.6 or later.
• PostgreSQL 9.3.4 or later.
• A weighted partial MaxSAT solver. Any MaxSAT solver using input and output format specified by the MaxSAT evaluation suffices. We recommend MiFuMaX.
• LBX.
• (Optional) MCSLs.
• (Optional) Gurobi.
• Z3.

Note: if you are only using the ALPS engine, Z3 should be sufficient.

Build

cd main; ant

Setup

To use Nichrome MLN engine, we need to first install and configure the PostgreSQL database, and provide a configuration file to help Nichrome find the software it depends on.

1. Install PostgreSQL. Download and unpack the source of PostgreSQL. Let PG_DIST be the path where the source is unpaked and PG_INSTALL be the path where you want PostgreSQL to be installed, then build and install PostgreSQL as follows:

    cd PG_DIST
    ./configure –prefix=PG_INSTALL
    make; make install 
    cd PG_DIST/contrib/intarray 
    make; make install				
    cd PG_DIST/contrib/intagg 
    make; make install
   

Then configure PostgreSQL as follows:

	cd PG_INSTALL/bin
	./initdb -D ../data
	./pg_ctl -D ../data/ -l ../log  start
	./createuser -s -P Nichrome
	# Provide a password you like, e.g., Nichrome
	./createdb Nichromedb

2. Define a configuration file. Below is an example configuration file, which we will refer to as "Nichrome.conf".

    db_url = jdbc:postgresql://localhost:5432/Nichromedb
   
    # Database username; must be a superuser
    db_username = Nichrome
   
    # The password for db_username
    db_password = Nichrome
   
    # The working directory; Nichrome may write sizable temporary data here
    dir_working = <work-dir>
   
    maxsat = <path of the MaxSAT solver>
    lbx = <path of lbx>
    mcsls = <path of mcsls>
   

Examples

TBD