public Attribute[] getAttributes(){ return (Attribute[]) this.list.toArray( new Attribute[ this.list.size() ] );
public Variable[] getAttributes(){ return (Variable[]) this.list.toArray( new Variable[ this.list.size() ] );
	public Attribute[] getAttributes(){		return (Attribute[]) this.list.toArray( new Attribute[ this.list.size() ] );	}