wytp.proof.rules.function

Class MacroExpansion

java.lang.Object

wytp.proof.util.AbstractProofRule

wytp.proof.rules.function.MacroExpansion

All Implemented Interfaces:

Proof.LinearRule, Proof.Rule

public class MacroExpansion
extends AbstractProofRule
implements Proof.LinearRule

Responsible for inlining macro invocations from their definitions. For example, consider this assertion:

 define nat(int n) is:
   n >= 0

 assert:
   forall(int x):
       if:
           x > 0
       then:
           nat(x)
 

In proving this assertion, we will at some point come to the macro invocation nat(x) or its inversion !nat(x). To deal with this, we simply replace nat(x) by its body where the parameters are substituted for their arguments. That is, we replace nat(x) by n >= 0 and substitute n for the argument x.

NOTE: A pretty obvious concern with this rule is how to deal with recursive macro definitions. This has not been tried and tested at this stage!

Author:

David J. Pearce

Field Summary

Fields inherited from class wytp.proof.util.AbstractProofRule

simp, types

Constructor Summary

Constructors

Constructor and Description
MacroExpansion(Simplification simplify, TypeSystem types)

Method Summary

Modifier and Type	Method and Description
Proof.State	apply(Proof.State state, Formula truth)
String	getName() Get the name of this rule

Methods inherited from class wytp.proof.util.AbstractProofRule

apply, extractDefinedTerms, findAllInstances, substitute

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface wytp.proof.Proof.LinearRule

apply

Constructor Detail

MacroExpansion

public MacroExpansion(Simplification simplify,
                      TypeSystem types)

Method Detail

getName

public String getName()

Description copied from interface: Proof.Rule

Get the name of this rule

Specified by:

getName in interface Proof.Rule

Returns:

apply

public Proof.State apply(Proof.State state,
                         Formula truth)
                  throws wybs.lang.NameResolver.ResolutionError

Specified by:

apply in class AbstractProofRule

Throws:

wybs.lang.NameResolver.ResolutionError