Sequences, Sarcasm

[From Rick Marken (960113.1300)]


The gain, g, you are talking about is not _loop_ gain; it
is the linear operator in an open loop sequential process:

  X(n) < g*X(n-1)

Bruce Abbott (960113.1450) --

How can a sequential process in which X ----> X be open loop?

Because X(n-1) is not having an effect on X(n) _while_ X(n)
is having an effect on X(n-1). Your equation describes a
system with one direction of causality -- from X(n-1) to X(n);
that's _open loop_; there is no causal loop.

Here is the diagram:
                           X -------[f(X)]
                           ^ |
                           > >

This is a delay loop; not a closed causal loop. Nice try, but
no cigar.

Your sarcasm is neither deserved nor does it belong on CSGNET.

Obviously, I disagree.