Ibo is the future of eo--I go. I guess our source is trying to indicate the separate uses of εἰμι as sum (I am) and ibo (I shall go). Of course in the GNT εἰμι tends toward the first, at least when it appears without a prefix. I'm not sure precisely how ibo is relevant to GNT: εἴσειμι appears 4 times, all of them meaning something close to enter, without tense being much of an issue. In other words, the 'go' part works, but the choice of the future in Latin doesn't seem to apply.
Edited by Philip, 17 March 2020 - 09:51 PM.