[Vextasy]

Yes, you could be right there. Perhaps that was why.

I do remember being grateful (in later versions of BASIC) for the RENUMBER command, which does not appear in this early version, but which allowed you to create space between lines to insert new ones.

The other reason that it might have seemed pertinent to the writer was that CARDBASIC (page 50), in which each line of program appears on a card, also requires you to place a line number on a card, and so the order of cards in the deck would not have been important.