atom, yielding atoms
such as 8304efdd-bd6e-5b7c-a27f-83f3f05c64e0. The
alternative is integer, returning a large integer that
represents the 128 bits of the UUID.
If SWI-Prolog was not built with the OSSP UUID dependency library a
simple Prolog alternative that only implements version 4 random
UUIDs is provided. In this case the default version is 4 and the
only admissible options are version(4) and format(Format).