simp only [rst_iso, Model.rst_iso, one_pow, mul_zero, one_mul,
add_zero, mul_assoc, ←pow_two t, zero_mul, mul_add, sub_sub]
R : Type u
inst✝ : CommRing R
e : ValidModel R
s t : R
⊢ (rst_iso 0 s t e).toModel.a6 = e.a6 - t * e.a3 - t ^ 2
no goals