static Web web_ifThen2(Web inputWeb, Web web) {

  Web patternWeb, Map<WebNode> patternMap = unpair cloneWebWithMap(web);

  web_dropRelationsStartingWith(patternWeb, "Then:");

  Collection<WebNode> adders = mapUsingMap(reversedMap(patternMap), web_singleNodes(patternWeb));

  web_dropSingleNodes(patternWeb); // To remove things only linked through "then" relations

  Web thenWeb, Map<WebNode> thenMap = unpair cloneWebWithReverseMap(web);

  web_unpackRelationsStartingWith(thenWeb, "Then:");

  Map<WebNode> match = web_matchAllPerms_partial(patternWeb, inputWeb);

  if (match != null) {

    print("Have match. Adders: " + adders);

    // Add new nodes first

    new HashMap<WebNode> adderMap;

    for (WebNode n : adders) { // adders are in "web" space

      WebNode inputNode;

      WebNode thenNode = reverseLookup(thenMap, n);

      web_setLabels(inputNode = inputWeb.newNode(), n.labels);

      adderMap.put(thenNode, inputNode);

    }

    // Then add relations from thenWeb

    for (WebRelation rel : web_relationObjects(thenWeb)) {

      WebNode a = or(mapGet(adderMap, rel.a), mapGet(match, mapGet(patternMap, mapGet(thenMap, rel.a))));

      WebNode b = or(mapGet(adderMap, rel.b), mapGet(match, mapGet(patternMap, mapGet(thenMap, rel.b))));

      if (a != null && b != null) {

        WebRelation rel2 = inputWeb.getRelation(a, b);

        web_addLabelsFromNodeToNode(rel, rel2);

      }

    }

  }

  ret inputWeb;

}