false n. the symbol nil, used to represent the failure of a
predicate test. fbound ['ef,band] adj. (of a function name)
bound in the function namespace. (The names of macros and
special operators are fbound, but the nature and type of the
object which is their value is implementation-dependent.
Further, defining a setf expander F does not cause the setf
function (setf F) to become defined; as such, if there is a such
a definition of a setf expander F, the function (setf F) can be
fbound if and only if, by design or coincidence, a function
binding for (setf F) has been independently established.) See
the functions fboundp and symbol-function. feature n. 1. an
aspect or attribute of Common Lisp, of the implementation, or of
the environment. 2. a symbol that names a feature. See Section
24.1.2 (Features). ``The :ansi-cl feature is present in all
conforming implementations.'' feature expression n. A boolean
combination of features used by the #+ and #- reader macros in
order to direct conditional reading of expre