@@ -155,6 +155,7 @@ theorem weightedOrder_eq_top_iff :
155155 f.weightedOrder w = ⊤ ↔ f = 0 := by
156156 rw [← not_iff_not, ← ne_eq, ← ne_eq, ne_zero_iff_weightedOrder_finite w, coe_toNat_eq_self]
157157
158+ set_option backward.isDefEq.respectTransparency false in
158159/-- If the order of a formal power series `f` is finite,
159160then some coefficient of weight equal to the order of `f` is nonzero. -/
160161theorem exists_coeff_ne_zero_and_weightedOrder
@@ -165,6 +166,7 @@ theorem exists_coeff_ne_zero_and_weightedOrder
165166 generalize_proofs h1
166167 exact Nat.find_spec h1
167168
169+ set_option backward.isDefEq.respectTransparency false in
168170/-- If the `d`th coefficient of a formal power series is nonzero,
169171then the weighted order of the power series is less than or equal to `weight d w`. -/
170172theorem weightedOrder_le {d : σ →₀ ℕ} (h : coeff d f ≠ 0 ) :
@@ -180,6 +182,7 @@ theorem coeff_eq_zero_of_lt_weightedOrder {d : σ →₀ ℕ} (h : (weight w d)
180182 coeff d f = 0 := by
181183 contrapose! h; exact weightedOrder_le w h
182184
185+ set_option backward.isDefEq.respectTransparency false in
183186/-- The order of a formal power series is at least `n` if
184187the `d`th coefficient is `0` for all `d` such that `weight w d < n`. -/
185188theorem nat_le_weightedOrder {n : ℕ} (h : ∀ d, weight w d < n → coeff d f = 0 ) :
@@ -191,6 +194,7 @@ theorem nat_le_weightedOrder {n : ℕ} (h : ∀ d, weight w d < n → coeff d f
191194 rw [← hd, Nat.cast_lt] at H
192195 exact hfd (h d H)
193196
197+ set_option backward.isDefEq.respectTransparency false in
194198/-- The order of a formal power series is at least `n` if
195199the `d`th coefficient is `0` for all `d` such that `weight w d < n`. -/
196200theorem le_weightedOrder {n : ℕ∞} (h : ∀ d : σ →₀ ℕ, weight w d < n → coeff d f = 0 ) :
@@ -201,6 +205,7 @@ theorem le_weightedOrder {n : ℕ∞} (h : ∀ d : σ →₀ ℕ, weight w d < n
201205 · apply nat_le_weightedOrder;
202206 simpa only [ENat.some_eq_coe, Nat.cast_lt] using h
203207
208+ set_option backward.isDefEq.respectTransparency false in
204209/-- The order of a formal power series is exactly `n` if and only if some coefficient of weight `n`
205210is nonzero, and the `d`th coefficient is `0` for all `d` such that `weight w d < n`. -/
206211theorem weightedOrder_eq_nat {n : ℕ} :
@@ -248,6 +253,7 @@ theorem min_weightedOrder_le_add :
248253 [coeff_eq_zero_of_lt_weightedOrder w, lt_min_iff, map_add, add_zero,
249254 imp_true_iff]
250255
256+ set_option backward.isDefEq.respectTransparency false in
251257private theorem weightedOrder_add_of_weightedOrder_lt.aux
252258 (H : f.weightedOrder w < g.weightedOrder w) :
253259 (f + g).weightedOrder w = f.weightedOrder w := by
@@ -478,6 +484,7 @@ theorem le_order_prod {R : Type*} [CommSemiring R] {ι : Type*}
478484 (f : ι → MvPowerSeries σ R) (s : Finset ι) : ∑ i ∈ s, (f i).order ≤ (∏ i ∈ s, f i).order :=
479485 le_weightedOrder_prod _ _ _
480486
487+ set_option backward.isDefEq.respectTransparency false in
481488theorem one_le_order_iff_constCoeff_eq_zero :
482489 1 ≤ f.order ↔ f.constantCoeff = 0 := by
483490 constructor
@@ -617,6 +624,7 @@ theorem weightedHomogeneousComponent_of_lt_weightedOrder_eq_zero
617624 exact hf
618625 · rw [map_zero]
619626
627+ set_option backward.isDefEq.respectTransparency false in
620628variable {w} in
621629theorem weightedHomogeneousComponent_of_weightedOrder
622630 {f : MvPowerSeries σ R} {p : ℕ} (hf : p = f.weightedOrder w) :
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