abagraph

Requirements

The code has been tested using SICStus Prolog (4.2+) on Linux. To use the optional visualization of solutions, you also need graphviz.

Installation

Download the source: abagraph.tar.gz. Unzip and untar it somewhere. Make sure the BASH abagraph script from 'scripts/' is somewhere in your PATH. Edit two variables at the top of the script to point to the right places.

Invocation

If you've followed the directions for the script, above, you can do either:

• % abagraph      OR
• % abagraph source.pl

where 'source.pl' is the name of a Prolog source file for the ABA framework. Alternatively, you can go to the 'code/' directory, load prolog, and just do:

• ?- [abagraph].      OR
• ?- compile(abagraph).

Basic Usage

Once abagraph is loaded, you can (re)load a source file (named 'source.pl') using:

• ?- loadf(source).

To find a derivation for the sentence 's', do:

• ?- derive(s, X).

The solution will be printed on screen, and 'X' bound to an internal representation of it. Printed on screen is the Proponent argument graph (PGRAPH), the defence set (DEFENCE), the set of Opponent argument graphs (OPGRAPHS), and the culprits (CULPRITS).

Doing

• ?- help.

prints some usage information.

Options

Current values of options are displayed by:

• ?- options.

To print the derivation steps during a call to sxdd/2, use:

• ?- set_verbose.

To hide the derivation steps (default), use:

• ?- set_quiet.

To output the solutions, as found, to a '.dot' file for visualization with graphviz, use:

• ?- set_print.

To set not to print, use:

• ?- set_noprint.

To use AB-dispute derivations, do:

• ?- set_ab.

To use GB-dispute derivations, do:

• ?- set_gb.

To change strategies, use:

• ?- set_strategies(StratList).

StratList has the form: [T,OJ,PS,OS,PR].

turn choice (T):

• p - proponent priority [DEFAULT]
• o - opponent priority
• s - smallest number of sentences/justification-pairs first

opponent justification set choice:

• n - newest
• o - oldest
• s - smallest set of pending (unmarked) sentences [DEFAULT]
• l - largest set of pending (unmarked) sentences
• lmb - lowest maximum 'branching' coefficient

sentence choice (proponent PS, and opponent OS):

• n - newest
• o - oldest
• e - eager (choose an assumption if possible)
• p - patient (choose non-assumption if poss.) [DEFAULT (prop and opp)]
• be - sentence with smallest 'branching' coefficient (eager)
• bp - sentence with smallest 'branching' coefficient (patient)

proponent rule choice (PR):

• s - smallest rule body first
• l1 - look-ahead, 1-step [DEFAULT]

Example

The source file toni6_2.pl is included in the distribution. A query of 'derive(p, X)' writes the solution to screen:

When visualized using graphviz, this is:

Proponent argument graph shaded blue; marked Opponent argument graphs shaded grey; unmarked (non-empty unmarked support) Opponent argument graphs shaded white. Defence set green. Culprits yellow. Attacks in red.