Empty

interface Empty: Atom, Any

Methods

freshCopy

open fun freshCopy(): Empty

Returns a fresh copy of this Term, that is, an instance of Term which is equal to the current one in any aspect, except variables directly or indirectly contained into this Term, which are refreshed. This means that it could return itself, if no variable is present (ground term), or a new Term with freshly generated variables.

Variables are refreshed consistently, meaning that, if more variables exists within this Term having the same name, all fresh copies of such variables will have the same complete name.

Example: "f(X, g(X))".freshCopy() returns something like "f(X_1, g(X_1))" instead of "f(X_1, g(X_2))"

Notice that, if the current term is ground, the same object may be returned as a result by this method.

ReturnValue

Name Description
Empty

a fresh copy of the current term which is different because variables are consistently renamed

freshCopy

open fun freshCopy(scope: Scope): Empty

Returns a fresh copy of this Term, similarly to freshCopy, possibly reusing variables from the provided scope, if any

Parameters

Name Description
scope: Scope

the Scope containing variables to be used in copying

ReturnValue

Name Description
Empty

a fresh copy of the current term which is different because variables are consistently renamed

Extensions

extractSignature

fun Struct.extractSignature(): Signature

Extracts this Struct indicator and converts it to Signature

Receiver

Name Description
Struct

ReturnValue

Name Description
Signature

unfoldGoals

fun Term.unfoldGoals(): Sequence<Term>

Receiver

Name Description
Term

ReturnValue

Name Description
Sequence<Term>

toGoals

fun Term.toGoals(): Cursor<Term>

Receiver

Name Description
Term

ReturnValue

Name Description
Cursor<Term>

isWellFormed

fun Term.isWellFormed(): Boolean

Check whether the receiver term is a well-formed predication

Receiver

Name Description
Term

ReturnValue

Name Description
Boolean

prepareForExecutionAsGoal

fun Term.prepareForExecutionAsGoal(): Struct

Prepares the receiver Goal for execution

For example, the goal A is transformed, after preparation for execution, as the Term: call(A)

Receiver

Name Description
Term

ReturnValue

Name Description
Struct

eq

infix fun Term.eq(that: Term): Equation<Term, Term>

Creates an equation with this and that terms

Receiver

Name Description
Term

Parameters

Name Description
that: Term

ReturnValue

Name Description
Equation<Term, Term>

CompanionObject

Empty

interface Empty: Atom, Any

Fields

Name Description
const EMPTY_LIST_FUNCTOR: String
const EMPTY_SET_FUNCTOR: String

Methods

list

fun list(): EmptyList

ReturnValue

Name Description
EmptyList

set

fun set(): EmptySet

ReturnValue

Name Description
EmptySet