# The EQKEY signature

## Overview

The EQKEY signature defines an abstract type t and provides equality and toString functions on values of such type.

## Interface

 type t val equal : t * t -> bool val toString : t -> string 

## Types

type t
The abstract type as described in the overview.

## Values

val equal : t * t -> bool
(equal (x, y)) evaluates to true if and only if $x$ and $y$ are equal values of type t.
val toString : t -> string
(toString k) evaluates to a string representation of $x$, a value of type t.