The location of <aiin> and <ain> groups

[nickpelling]

This observations can be explained as an unintended side effect of the autocopying method. The source for the first word in each line could only be found within the previous lines. Since the first and the last word in each line are easy to spot, the most obvious way is to pick them as a source for the generation of a word at the beginning or at the end of a line.  For the second word it is also possible to select the first word as a source. Since the first word in a line usually has a prefix the simplest change is to remove this prefix.

But isn't there a completely different statistical result (I vaguely recall Mark Perakh mentioning it some years ago, but I suspect that even by then it was a commonplace) that says that the first word of each line is on average slightly longer than all the other words in the line, not just the second word?

The proposal that this kind of thing holds true for the first word of a page or paragraph is now well-established in Voynich analysis, but less so for non-paragraph-initial and non-page-initial words.

If this is correct for all lines (not just paragraph-initial and page-initial lines), then it strongly suggests that (a) it is not the first word in a line that gets shortened into some second word by having some putative prefix removed and/or by autocopying, but instead (b) that the first word is typically longer than all the other words because an entirely separate process is going on there, one that prepends an extra letter to the first word of each line.