//book\[price = /store/book\[3]/price] | $..book\[?(@.price === @root.store.book\[2].price)] | Filter all books whose price equals the price of the third book | @root is not present in the original spec

//book/../\*\[. instance of element(\*, xs:decimal)\] (in XPath 2.0) | $..book..\*@number() | Get the numeric values within the book array | @number(), the other basic types (@boolean(), @string()), other low-level derived types (@null(), @object(), @array()), the JSONSchema-added type, @integer(), the compound type @scalar() (which also accepts `undefined` and non-finite numbers for JavaScript objects as well as all of the basic non-object/non-function types), the type, @other(), to be used in conjunction with a user-defined callback (see `otherTypeCallback`) and the following non-JSON types that can nevertheless be used with JSONPath when querying non-JSON JavaScript objects (@undefined(), @function(), @nonFinite()) are not present in the original spec

//book/*[name() = 'category' and matches(., 'tion$')] (XPath 2.0) | $..book.*\[?(@property === "category" && @.match(/TION$/i))] | All categories of books which match the regex (end in 'TION' case insensitive) | @property is not present in the original spec.

| | `` ` `` (e.g., `` `$`` to match a property literally named `$`) | Escapes the entire sequence following (to be treated as a literal) | `` ` `` is not present in the original spec; to get a literal backtick, use an additional backtick to escape

Any additional variables supplied as properties on the optional "sandbox"