In this scenario, a variable can be equal to A or something other than A (we'll call that B).

Here are three presuppositions:

1) Variable X is equal to Variable Y (e.g. if Variable X is A, then Variable Y is A; if Variable X is B, then Variable Y is B; If Variable Y is A, then Variable X is A; if Variable Y is B, then Variable X is B)

2) Variable Y is freely given a value of A or B by an unencumbered human being on day 2

3) On day 1, Variable X has a fixed value of either A or B. If it is A, then it remains A forever. If it is B, then it remains B forever.

Can all three of those presuppositions be true?