[pron]

In every formal system, such as FOL/ZFC, all operators must have a precise meaning. And while it is true that most informal uses of the `=` sign in mathematics could be translated to some formal expression making use of a precisely-defined `=` sign, I think the point was that some (or most) mathematical notation is not formal, and therefore saying that `=` always means a precise notion of equality is wrong, even if in a particular formal language it always has this precise meaning. Therefore, this is not a sin to use the same `=` sign in some other formal language (say, a programming language) to mean something other than its meaning in a particular mathematical formal language.

[jcranberry]

I agree with your interpretation of the article, but I find that the article doesnt match the title. I think the equals sign almost always represents usage of an RST equivalence of some sort, even if the formula containing it isnt an equality (with the irritating exception of Big O notation).

However, I think that using this as a justification for programming languages' use of the equals sign for assignment (whether or not it needs any justification at all) I think is a moot point because mathematics is more expository, and isnt always strictly rigorous as long as its clear that everything is well defined and correct in the end (although there is expressiveness in the formalities as well).