Tokens are sequences of characters which are treated as separate symbols. Tokens include the symbols for variables, constants and functors, as well as punctuation characters such as brackets and commas. Two tokens must be separated by a layout-text token if they could otherwise be interpreted as a single token. Layout-text tokens are ignored when interpreting the token list as a term, and may appear at any point in the token list. Depending on the section, a category may represent a class of either terms, token lists, or character strings.
C denotes an optional C .
The common subset includes characters such as TAB , LFD , and SPC . The common subset includes the letters a through z . The common subset is the letters A through Z . Character escaping can be turned off for compatibility with old code. A single layout character, for example a newline, is ignored.