static bool tripleEqic(T3<S> a, T3<S> b) {
  if (a == null) ret b == null;
  else if (b == null) false;
  ret eqic(a.a, b.a) && eqic(a.b, b.b) && eqic(a.c, b.c);
}

static bool tripleEqic(T3<S> a, S ba, S bb, S bc) {
  if (a == null) false;
  ret eqic(a.a, ba) && eqic(a.b, bb) && eqic(a.c, bc);
}

ifclass Symbol
static bool tripleEqic(T3<Symbol> a, Symbol ba, Symbol bb, Symbol bc) {
  if (a == null) false;
  ret eqic(a.a, ba) && eqic(a.b, bb) && eqic(a.c, bc);
}
endif