static L> differencesElementByElement_codeTokensOnly(L a, L b) { L> l = new L; if (l(a) != l(b)) ret l; int n = l(a); for (int i = 1; i < n; i += 2) { A aa = a.get(i); A bb = b.get(i); if (neq(aa, bb)) l.add(triple(aa, bb, i)); } ret l; }