I wonder if that means that there is in principle a systematic operation by which one could extract, say, "Macbeth" from pi...

I’m sorry, I don’t follow. Is this an obscure joke I’m not getting? I see nothing in what I wrote that would suggest or imply such a thing. Within the prescribed circumstances, a systematic extraction of digits will typically extract random (or, more accurately, pseudorandom) digit sequences. Of course, you could always use some existing pattern’s encoding, e.g. the text of a Shakespearean play, as a basis for defining

*how* digits are to be extracted.

I meant just dropping the decimal point, without further "operations".

In that case, you’d just end up with an integer, albeit one that is infinitely long. The set of all integers is a proper subset of the rational numbers and so cannot be irrational.

'Luthon64