Formal definition of self-reproduction
may
have importance the Alife research program, especially for
application of its achievements outside the discipline. The paper
examines two formal definitions of self-reproduction, suggested by
McMullin and Löfgren. It is pointed out that these definitions
form two major branches of self-reproduction analysis, described by
ancestor-progeny and system-environment relationship. The
ancestor-progeny definition allows to distinct between the exact /
inexact reproduction. The system-environment definition brings in
the original classification also allowing to differentiate between
major classes of self-reproducers.