A fixnum is an integer whose value is between most-negative-fixnum and most-positive-fixnum inclusive. Exactly which integers are fixnums is implementation-defined.
The type fixnum is required to be a supertype of (signed-byte 16)
.
\issue{REAL-NUMBER-TYPE:X3J13-MAR-89} \issue{FIXNUM-NON-PORTABLE:TIGHTEN-DEFINITION}