int varchain::compare(const varchain& l, const varchain& r) {
size_t n = l.size() < r.size() ? l.size() : r.size();
for (size_t i=0; i<n; i++) {
if (l.repr[i] < r.repr[i]) {
return -1;
}
if (r.repr[i] < l.repr[i]) {
return 1;
}
}
if (l.size() < r.size()) return -1;
if (l.size() == r.size()) return 0;
return 1;
}
varchain operator * ( varchain c1, const varchain& c2 ) {
c1.repr.reserve(c1.size() + c2.size());
for (auto e : c2.repr) c1.repr.push_back(e);
c1.normalize();
return c1;
}