Section 3.3. "SELECT" only comes first if you omit "FROM". In SQL, if it allowed, that would be something like: `SELECT table.column`.

Tuple Variables and their Range?

I don’t think I see what you see. From 3.3:

    RANGE PART P
    GET W (P.P#,P.PNAME,P.QOH):(P.QOH<25)

Which approximately translates to:

   SELECT p.pnum, p.pname, p.qoh FROM part p WHERE p.qoh < 25

But a more direct translation would look something like:

   FROM part p SELECT p.pnum, p.pname, p.qoh WHERE p.qoh < 25

Even closer would be:

   FROM part p; SELECT p.pnum, p.pname, p.qoh WHERE p.qoh < 25

Of course they are different languages so we can only take things so far, but the pertinent bit is that the range specifier is declared first in ALPHA, whereas it is declared later, after the projection is defined, in SQL.