Recall that true and false are Vesta values, not C++ quantities.
t_bool operator==(t_bool b1, t_bool b2)
t_bool operator!=(t_bool b1, t_bool b2) operator!(operator==(b1, b2))
t_bool operator!(t_bool b) = { int ib = b; // convert to C++ integer if (ib) return false; else return true; }