static int tok_forall(L<S> tok, Matches m) {
  if (!(eqGet(tok, 1, "forall") && eqGet(tok, 3, "("))) ret -1;
  int argsFrom = 5;
  int iClosing = indexOf(tok, argsFrom, ")");
  assertTrue(iClosing >= 0);
  assertEquals(get(tok, iClosing+2), "{");
  int iEnd = findEndOfBlock(tok, iClosing+2)-1;
  setMatches(m, joinSubList(tok, argsFrom, iClosing-1),
    joinSubList(tok, iClosing+4, iEnd-1));
  ret iEnd+2;
}