# PTAH inequality

## Primary tabs

Type of Math Object:
Theorem
Major Section:
Reference

## Mathematics Subject Classification

### PTAH question

So, what does "PTAH" stand for?

bob1

i don't know.

### Re: PTAH question

Is it in connection to the ancient Egyptian god Phtah?
(http://en.wikipedia.org/wiki/Ptah)

### Re: PTAH question

Since you have rejected most of my corrections, the entry is still useless to anyone who has not read the paper you refer to. For example, why did you reject my correction about the a.e [m] abbreviation? This notation is quite unclear to me, and instead of rejecting and explaining just to me what it means, it would be much clearer if you explained this notation yourself in the entry or at least add a link to an entry where this misterious notation is explained, or at least add entries to the "see also" list for the background needed to read this entry. And again, the lambda_i's appear out of nowhere, it would be better to define at least \lambda=(\lambda_1,...), and \sigma as a collection of \lambdas.

Alvaro

### Re: PTAH question

Mathprof,

I see that you have (quietly) accepted my suggestions and made the suggested changes in the PTAH entry. So, why were my corrections rejected in the first place?

Alvaro

### Re: PTAH question

The folklore at the Institute for Defense Analyses in Princeton NJ
is that the first program to maximize a function P(z) by iterating the growth transformation
z --> zbar

was written while the programmer was listening to the opera Aida,
in which the Egyptian god of creation Ptah is mentioned, and that became the name of the program (and of the inequality). The name is in upper case because the word processor in use in the middle 1960's had no lower case.