Section 6.2 Familiarize yourself with the RELAX-NG schema
From the section on RELAX-NG schema in [2]: “A schema is a set of patterns which describe how the elements of a language may be combined. The PreTeXt vocabulary is described by a RELAX-NG schema”.
As you experiment, you should start getting used to the “RELAX-NG schema.” If you do not follow the schema, your PTX code may not compile correctly, and even if it does compile correctly, it may not do so after an update to the
mathbook repo.A decription for the RELAX-NG schema can be found at
http://mathbook.pugetsound.edu/doc/schema/. For instance, if you select the element <example> in the left-hand column, you will see lists of elements under the headings “Content model elements” and “Included in content model of elements.” The former list contains the elements that the <example> element may contain, and the latter contains the elements in which the <example> element may be contained.
