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HELP ATOM Steven Hardy, January 1978 Updated R. Barrett, January 1986 atom(<item>) -> <boolean> This procedure returns <false> if applied to a *PAIR, that is an object to which the procedures *FRONT and *BACK can be applied. Otherwise it returns <true>. Examples: atom([]) => ** <true> atom("x") => ** <true> atom([a b c d]) => ** <false> ATOM could be defined as: define atom(x); not(ispair(x)) enddefine; Attempting to apply HD or TL to an ATOM results in a MISHAP. Note that [], the empty list, is an ATOM. See also HELP * NULL, * CONSPAIR, * FRONT, * BACK, * DESTPAIR, * HD, * TL. For technical details see REF * LISTS