Remove undefined functions

interface/HUTN/includes/object_operations.alh

@@ -2,9 +2,6 @@ Element function allInstances(a: Element, b: Element)
 Element function allOutgoingAssociationInstances(a: Element, b: Element, c: Element)
 Element function allIncomingAssociationInstances(a: Element, b: Element, c: Element)
 Element function readElementByName(a: Element, b: String)
-Element function findAttribute(a: Element, b: Element, c: Element, d: Element)
-Element function readAttribute(a: Element, b: Element, c: String)
-Element function deleteAttribute(a: Element, b: Element, c: Element)
 Element function getAttributeList(a: Element, b: Element)
 Element function getInstantiatableAttributes(a: Element, b: Element)
 String function getName(a: Element, b: Element)