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commonlisp types

re: There seems to be nothing in CLtL that answers the question:
        "is x a legal type specifier?"

At the meeting that founded the X3J13 committee (on 6-Dec-85), Guy Steele 
circulated a list of "non-controversial issues" and "Clarifications"
which included the following addition [typos faithfully reproduced]:

  "(*) 51 Add a newefunction TYPE-SPECIFIER-P that is true of valid type
   specifiers and fals of all other Lisp objects.  Note that the use of
   DEFSTRUCT and DEFTYPE can change the behavior of TYPE-SPECIFIER-P over
   time."

Sad to say, this and many other "non-controversial" items included in
Guy's list of "Clarifications", has never been brought up in the X3J13
"Cleanup" subcommittee.  However, Lucid's 3.0 release includes such 
a function.


-- JonL --