Theorem 15.1.2 (I. Newton). Optional.
Here’s the statement of the theorem.
<proposition>have the same structure in PreTeXt, so we will just illustrate
theorem. You can actually put another
proofright after this one if you want to.
<title>is optional and typically used for theorems with names. To give an attribution, one can use the optional
<creator>tag. Cross references (see Section 22.1) can be made using the name or the number, depending on how the author codes them.
<proof>elements. In such instances, it would be useful to use the
<title>tag within your proof. By default, a
<proof>is hidden in a knowl when using HTML output. Click the “Proof.” heading to expand the proof. Click it again to hide the proof. A
<proof>can also be divided into
<case>s, each of which can have a title. Although it has not always been so, you can author a
<proof>all on its own within a division. The structure of such a detached
<proof>is the same as for a
<proof>contained within a theorem-like element.
<theorem>, but a
<definition>does not have a proof. You are encouraged to use the
<term>tag to set off the word being defined. If you wish to include a list of notation as an appendix as your document, you might also add a
<notation>tag such as shown in Listing 15.1.3. A
<notation>tag has no effect unless you have an