The macro DEFINESYMBOL takes one argument, an identifier, which is treated as a symbol that is set to the logic value `true'. The true-ness or false-ness of this symbol may subsequently be tested with IFDEF (see section ??). The corresponding macro UNDEFINESYMBOL removes the definition of a symbol. Example:
Definining "somesymbol"...
DEFINESYMBOL(somesymbol)
IFDEF(somesymbol)
    (Symbol "somesymbol" is true.)
    (Symbol "somesymbol" is false.)

Removing definition of "somesymbol"...
UNDEFINESYMBOL(somesymbol)
IFDEF(somesymbol)
    (Symbol "somesymbol" is true.)
    (Symbol "somesymbol" is false.)

This produces output similar to:

Definining "somesymbol"...
Symbol "somesymbol" is true.
Removing definition of "somesymbol"...
Symbol "somesymbol" is false.

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Copyright (c) 1997, 1998, 1999 Karel Kubat and Jan Nieuwenhuizen.

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