x1 = true;
x2 = true;
x3 = false;
eq = 1;
----------
x1 = false;
x2 = true;
x3 = false;
eq = 2;
----------
x1 = true;
x2 = false;
x3 = true;
eq = 2;
----------
x1 = false;
x2 = false;
x3 = true;
eq = 3;
----------
==========