Difference between revisions of "RuleTransformation"

Revision as of 20:39, 21 August 2013

Overview

Inference rules are represented in human-readable format. This page describes the transformation of these rules into Tuffy's MLN syntax.

We first define a general purpose tuple predicate (T) that can represent n-ary and nested tuples.

T(arg1:String, rel:String, arg2:String, arg3:String, narg1:String, nrel:String, narg2:String)

Rules that specify when two arguments match (e.g., under synonymy, stemming, and/or dropping of modifiers) need to be enumerated out for each argument position.

Types of transformations

Equality under stemming will be covered by the following rules:

T(a1, rel, a2, a3, na1, arel, na2), stem(a1, x) => T(x, rel, a2, a3, na1, nrel, na2)
T(a1, rel, a2, a3, na1, arel, na2), stem(rel, x) => T(a1, x, a2, a3, na1, nrel, na2)
T(a1, rel, a2, a3, na1, arel, na2), stem(a2, x) => T(a1, rel, x, a3, na1, nrel, na2)
...
...

Equality under head word transformations will be covered by the following rules:

T(a1, rel, a2, a3, na1, arel, na2) [headword(a1) == x || headword(x) == a1] => T(x, rel, a2, a3, na1, nrel, na2)
...
...


Allowing the argument with "something" to match any value. 

T(a1, rel, "something", a3, na1, nrel, na2) => T(a1, rel, x, na1, nrel, na2)
...

Example 1

Question to demonstrate: “Growth causes leaves of a plant to become large”.

(growth, cause,  (leaves of a plant, become large))	[nested, with intransitive arg2] 
(growth, cause,  (leaves of a plant, become, large))	[nested, with binary rel for arg2]

Evidence from definition: “The noun growth is the process of something becoming bigger”

(growth, is process of, (something, become bigger)
(growth, is process of, (something, become, bigger))

Rules needed

(((

1. Rel: X => Rel: is process of [generalize any action to “is process of”]

1a. Rel: cause => Rel: is process of [more particular version of rule 2]

2. Rel: is process of => Rel: X [abductive rule, inverse of rule 1]

2a. Rel: is process of => Rel: cause [abductive rule, inverse of rule 1a]

3. Arg: X => Arg: something [generalize any arg value to “something”]

4. Arg: something => Arg: X [abductive rule, inverse of rule 3]

5. Rel: become bigger => Rel: become big [lexical substitution from verb stemmer]

6. Rel: become big => Rel: become large [lexical substitution from WN synonym]

)))

Notes on rules:

We can derive abductive inverses automatically with a meta-rule. Lexical substitution rules are generated on the fly as needed.

Derivation

Evidence: 
	(growth, is process of, (something, become bigger)) 
Rel: become bigger   =>  Rel: become big
	(growth, is process of, (something, become big))
Rel: become big  =>  Rel: become large
	(growth, is process of, (something, become large))
Arg: something  =>  Arg: X
	(growth, is process of, (leaves of a plant, become large))
Rel: is process of  =>  Rel: X
	(growth, cause,  (leaves of a plant, become large))   QED