static int gSearchNeqNoSystemIdx(L<S> log, O predicate) {
  ret gSearchNeqNoSystemIdx(log, predicate, 1); // no sense to start from 0
}

static int gSearchNeqNoSystemIdx(final L<S> log, final O predicate, int startIdx) {
  ret gSearchIdx(log, func(S s) {
    neq(s, gI(log)) && !isSystemLine(s) && isTrue(callF(predicate, s))
  }, startIdx);
}