Throughout this document we shall use the following notation: square brackets ([]) shall denote the default value of a variable, braces ({}) denote optional items, and a name enclosed in angle brackets (<>) denotes the current value of that name. Square brackets are also used to delimit indices in REDTEN, however the usage should be clear from the context. REDUCE and REDTEN keywords, variables, and functions will be indicated in typewriter font. User input will be shown in a slanted typewriter font.
Certain REDUCE and REDTEN variables contain special characters that are not ordinarily considered to be alpha-numeric. These characters (most often '*', and occasionally '-') must be quoted with the escape-character, !, so for example to enter coords* one must type coords!*. Forgetting to escape the special character can have unexpected consequences, since these special characters usually have other meanings by themselves. In this manual we shall always indicate the escape character as if it were an actual part of the name, however, depending on the print mechanism used, identifiers with special characters may or may not be displayed with an embedded escape-character. The escape-character can also be used to suppress the case-folding of the system, if this has been re-enabled.
When showing the format of a call to a function, the type of each argument is shown following the argument name and separated by a colon. In some cases the type of the return value is indicated after the function call template. The argument types are described in C.1.