Как перевести с английского одно предложение?

[gefest_md]

Контекст такой.

Цитата:

Let $N$ be the structure $(\mathbb{N}|s)$ that interprets the unary function $s$ as the successor function. ... Only those subsets of $\mathbb{N}$ that are closed under $s$ may serve as the universe of a substructure. The closed subsets of $\mathbb{N}$ are the sets of the form $\{n\mid n\geqslant d\}$ for some $d\in\mathbb{N}.$ It follows that there are countably many substructures of $N$. Moreover, all of these substructures are isomorphic. So there is only one substructure up to isomorphism.

Пожалуйста, дайте хороший перевод последней фразы: "there is only one substructure up to isomorphism".

[ИСН]

...с точностью до изоморфизма.

[Munin]

(напрашивается)

...и немедленно выпил.