The mzlib^ signature is defined by:
(define-signature mzlib^
((open mzlib:core^)
(unit compat : mzlib:compat^)
(unit print-convert : mzlib:print-convert^)
(unit date : mzlib:date^)
(unit inflate : mzlib:inflate^)
(unit command-line : mzlib:command-line^)
(unit restart : mzlib:restart^)))
The mzlib@ unit implements this signature by linking the mzlib:core@ unit together with the non-[CORE] standard library units.