There is no answer because you're saying that
3 Zeus's = the incident.
And 1 Zeus + Green Horse + 3 = the same incident.
And Green Horse - 2 = Zeus, but this one is not possible because according to the first 2
Green Horse + 3 is the same as 2 Zeus's, so how can that be, when
Green Horse - 2 is the same as 1 Zeus?