English
If rTensor on P.subtype t equals that on P'.subtype t', there exist Q with P ≤ Q and P' ≤ Q, Q.FG, such that rTensor on inclusions yield equality.
Русский
Если rTensor на P.subtype t равен rTensor на P'.subtype t', найдётся Q с P ≤ Q и P' ≤ Q, Q.FG, так что включения дают равенство.
LaTeX
$$$\\exists Q\\,(hPQ: P \\le Q)\\,(hP'Q: P' \\le Q), Q.FG ∧ rTensor N (inclusion hPQ) t = rTensor N (inclusion hP'Q) t'.$$$
Lean4
theorem eq_zero_of_fg_of_subtype_eq_zero (h : rTensor N P.subtype t = 0) :
∃ (Q : Submodule R M) (hPQ : P ≤ Q), Q.FG ∧ rTensor N (inclusion hPQ) t = 0 :=
by
rw [← (rTensor N P.subtype).map_zero] at h
simpa only [map_zero] using TensorProduct.eq_of_fg_of_subtype_eq hP h