static Web webFromTriple(Symbol a, Symbol b, Symbol c) {
  ret webFromTriple(triple(a, b, c));
}

static Web webFromTriple(Triple<Symbol> t) {
  if (t == null) null;
  ret webFromTriple(t, 0.2, 0.2, 0.8, 0.7);
}

static Web webFromTriple(Triple<Symbol> t, double x1, double y1, double x2, double y2) {
  if (t == null) null;
  Web web = webWithoutIndexAndLock(); // save space
  S a = unnull(str(t.a)), b = unnull(str(t.b)), c = unnull(str(t.c));
  
  // ensure we are making 3 nodes, even if texts are identical
  // ("singular is singular")
  WebNode nodeA = web.newNode(a), nodeC = web.newNode(c);
  web_addRelation(nodeA, nodeC, b);
  
  web_setPosition(first(web.nodes), x1, y1);
  web_setPosition(second(web.nodes), x2, y2);
  
  if (t instanceof TripleWeb) {
    TripleWeb w = cast t;
    web.globalID = w.globalID();
    web.created = w.created;
    web.source = w.source;
    web.unverified = w.unverified();
  }
  
  ret web;
}