Strange loop, arises when, by moving up or down through a
hierarchical system, one finds oneself back where one started.
So this is strange
A strange loop is a hierarchy of levels, each of which is linked
to at least one other by some type of relationship. A strange loop
hierarchy, however, is "tangled" (Hofstadter refers to this as a
"heterarchy"), in that there is no well defined highest or lowest
level; moving through the levels one eventually returns to the
starting point, i.e., the original level. Examples of strange loops
that Hofstadter offers include: many of the works of M. C. Escher,
the information flow network between DNA and enzymes through
protein synthesis and DNA replication, and self-referential
Gödelian statements in formal systems.
In I Am a Strange Loop, Hofstadter defines strange loops as
follows:
“ And yet when I say "strange loop", I have
something else in mind — a less concrete, more elusive
notion. What I mean by "strange loop" is — here goes a first
stab, anyway — not a physical circuit but an abstract loop in
which, in the series of stages that constitute the cycling-around,
there is a shift from one level of abstraction (or structure) to
another, which feels like an upwards movement in a hierarchy, and
yet somehow the successive "upward" shifts turn out to give rise to
a closed cycle. That is, despite one's sense of departing ever
further from one's origin, one winds up, to one's shock, exactly
where one had started out. In short, a strange loop is a
paradoxical level-crossing feedback loop. (pp. 101-102)
”
This Enfield not allowed on the loop
