The predicate for whether a dspec has a definition.
dspec
dspec-defined-p dspec => definedp
A dspec.
definedp
The canonical form of dspec if dspec is defined, or nil otherwise.
nil
The function dspec-defined-p determines whether the dspec dspec has a definition. If so, it returns the canonical form of dspec .
dspec-defined-p
If dspec has no definitions, dspec-defined-p returns nil .
CL-USER 23 > (dspec:dspec-defined-p '(function list))
(DEFUN LIST)