I came across this form in Reading Greek in one of their exercises. They take it as a 3rd plural, but shouldn’t that be συγχωρήσειαν with an alpha not an epsilon? I haven’t bothered to keep a record, but there seem to be a lot of little annoying mistakes in the textbook.
Yes, 3rd plur. should be either συγχωρήσειαν (the more common form)or συγχωρήσαιεν. συγχωρήσειε(ν) would be 3rd sing. Are you sure the verb form should be plural? (Though it doesn’t seem likely that this verb would have a neuter plural subject, requiring a singular verb.)
This is the exercise that you are referring to?
I don’t believe that the ἕως clause has to have the same subject as the main clause.
Serendipitously (or unluckily), I came across another συγχωρέω error yesterday, and was thinking about posting about it. It is P. G. W. Glare’s article in Hyperboreus about problems with the LSJ. He uses συγχωρέω as one of the examples of the LSJ sometimes incorrectly including meanings that are really only contextual in its glosses:
There seem to be some real gems in this journal, which I only found yesterday. Likely more, if you speak Russian.
Συγχωρεω
I checked some old dictionaries: Jacobitz, 1843, Handwörterbuch der griechischen Sprache, Vol. II p. 1200 and Passow 1857, Handwörterbuch der griechischen Sprache, Vol II.2 page 1606.
Both have the meaning „Platz machen, von seinem Orte weichen, zurücktreten od. Zurücken“.
Passow/Schneider
https://www.digitale-sammlungen.de/en/view/bsb10808503?page=304
At least LSJ was not standing alone in this.
Interesting semantic drift. In modern Greek, the way you say “excuse me” is Με συγχωρείτε. It’s the phrase I would use if I needed to squeeze my way through a crowd (which seems like LSJ’s second meaning), but it’s also what I would say if I wanted to get a stranger’s attention on the street to ask for directions. I don’t know if the latter usage is actually idiomatically correct or if I was just imputing the English phrase’s range of meanings to the Greek one – but people did seem to understand that I was trying to get their attention, and they did seem to accept it as polite behavior (although they were always incredibly nice and tolerant when it came to any foreigner’s efforts to speak any Greek at all).