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degree_zero : m.degree (0 : MvPolynomial σ R) = 0 := by simp [degree]
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
degree_zero
null
ne_zero_of_degree_ne_zero {f : MvPolynomial σ R} (h : m.degree f ≠ 0) : f ≠ 0 := by rintro rfl exact h m.degree_zero @[simp, nontriviality]
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
ne_zero_of_degree_ne_zero
null
degree_subsingleton [Subsingleton R] {f : MvPolynomial σ R} : m.degree f = 0 := by rw [Subsingleton.eq_zero f, degree_zero] @[simp]
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
degree_subsingleton
null
leadingCoeff_zero : m.leadingCoeff (0 : MvPolynomial σ R) = 0 := by simp [degree, leadingCoeff]
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
leadingCoeff_zero
null
Monic.ne_zero [Nontrivial R] {f : MvPolynomial σ R} (hf : m.Monic f) : f ≠ 0 := by rintro rfl simp [Monic, leadingCoeff_zero] at hf
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
Monic.ne_zero
null
degree_monomial_le {d : σ →₀ ℕ} (c : R) : m.degree (monomial d c) ≼[m] d := by simp only [degree, AddEquiv.apply_symm_apply] apply le_trans (Finset.sup_mono support_monomial_subset) simp only [Finset.sup_singleton, le_refl]
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
degree_monomial_le
null
degree_monomial {d : σ →₀ ℕ} (c : R) [Decidable (c = 0)] : m.degree (monomial d c) = if c = 0 then 0 else d := by simp only [degree, support_monomial] split_ifs with hc <;> simp
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
degree_monomial
null
degree_X_le_single {s : σ} : m.degree (X s : MvPolynomial σ R) ≼[m] Finsupp.single s 1 := degree_monomial_le 1
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
degree_X_le_single
null
degree_X [Nontrivial R] {s : σ} : m.degree (X s : MvPolynomial σ R) = Finsupp.single s 1 := by classical change m.degree (monomial (Finsupp.single s 1) (1 : R)) = _ rw [degree_monomial, if_neg one_ne_zero] @[simp] theorem degree_one : m.degree (1 : MvPolynomial σ R) = 0 := by nontriviality R classical rw [MvPolynomial.one_def, degree_monomial] simp @[simp]
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
degree_X
null
leadingCoeff_monomial {d : σ →₀ ℕ} (c : R) : m.leadingCoeff (monomial d c) = c := by classical simp only [leadingCoeff, degree_monomial] split_ifs with hc <;> simp [hc] @[simp] theorem monic_monomial_one {d : σ →₀ ℕ} : m.Monic (monomial d (1 : R)) := m.leadingCoeff_monomial 1
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
leadingCoeff_monomial
null
monic_monomial {d : σ →₀ ℕ} {c : R} : m.Monic (monomial d c) ↔ c = 1 := by rw [Monic, m.leadingCoeff_monomial]
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
monic_monomial
null
leadingCoeff_X {s : σ} : m.leadingCoeff (X s : MvPolynomial σ R) = 1 := m.leadingCoeff_monomial 1 @[simp] theorem monic_X {s : σ} : m.Monic (X s : MvPolynomial σ R) := monic_monomial_one
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
leadingCoeff_X
null
leadingCoeff_one : m.leadingCoeff (1 : MvPolynomial σ R) = 1 := m.leadingCoeff_monomial 1
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
leadingCoeff_one
null
monic_one : m.Monic (C 1 : MvPolynomial σ R) := monic_monomial_one
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
monic_one
null
degree_le_iff {f : MvPolynomial σ R} {d : σ →₀ ℕ} : m.degree f ≼[m] d ↔ ∀ c ∈ f.support, c ≼[m] d := by unfold degree simp only [AddEquiv.apply_symm_apply, Finset.sup_le_iff, mem_support_iff, ne_eq]
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
degree_le_iff
null
degree_lt_iff {f : MvPolynomial σ R} {d : σ →₀ ℕ} (hd : 0 ≺[m] d) : m.degree f ≺[m] d ↔ ∀ c ∈ f.support, c ≺[m] d := by simp only [map_zero] at hd unfold degree simp only [AddEquiv.apply_symm_apply] exact Finset.sup_lt_iff hd
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
degree_lt_iff
null
le_degree {f : MvPolynomial σ R} {d : σ →₀ ℕ} (hd : d ∈ f.support) : d ≼[m] m.degree f := by unfold degree simp only [AddEquiv.apply_symm_apply, Finset.le_sup hd]
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
le_degree
null
coeff_eq_zero_of_lt {f : MvPolynomial σ R} {d : σ →₀ ℕ} (hd : m.degree f ≺[m] d) : f.coeff d = 0 := by rw [← not_le] at hd by_contra hf apply hd (m.le_degree (mem_support_iff.mpr hf))
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
coeff_eq_zero_of_lt
null
leadingCoeff_ne_zero_iff {f : MvPolynomial σ R} : m.leadingCoeff f ≠ 0 ↔ f ≠ 0 := by constructor · rw [not_imp_not] intro hf rw [hf, leadingCoeff_zero] · intro hf rw [← support_nonempty] at hf rw [leadingCoeff, ← mem_support_iff, degree] suffices f.support.sup m.toSyn ∈ m.toSyn '' f.support by obtain ⟨d, hd, hd'⟩ := this rw [← hd', AddEquiv.symm_apply_apply] exact hd exact Finset.sup_mem_of_nonempty hf @[simp]
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
leadingCoeff_ne_zero_iff
null
leadingCoeff_eq_zero_iff {f : MvPolynomial σ R} : leadingCoeff m f = 0 ↔ f = 0 := by simp only [← not_iff_not, leadingCoeff_ne_zero_iff]
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
leadingCoeff_eq_zero_iff
null
coeff_degree_ne_zero_iff {f : MvPolynomial σ R} : f.coeff (m.degree f) ≠ 0 ↔ f ≠ 0 := m.leadingCoeff_ne_zero_iff
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
coeff_degree_ne_zero_iff
null
degree_mem_support_iff (f : MvPolynomial σ R) : m.degree f ∈ f.support ↔ f ≠ 0 := mem_support_iff.trans coeff_degree_ne_zero_iff @[simp]
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
degree_mem_support_iff
null
coeff_degree_eq_zero_iff {f : MvPolynomial σ R} : f.coeff (m.degree f) = 0 ↔ f = 0 := m.leadingCoeff_eq_zero_iff
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
coeff_degree_eq_zero_iff
null
degree_mem_support {p : MvPolynomial σ R} (hp : p ≠ 0) : m.degree p ∈ p.support := by rwa [MvPolynomial.mem_support_iff, coeff_degree_ne_zero_iff]
lemma
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
degree_mem_support
null
degree_eq_zero_iff_totalDegree_eq_zero {f : MvPolynomial σ R} : m.degree f = 0 ↔ f.totalDegree = 0 := by rw [← m.toSyn.injective.eq_iff] rw [map_zero, ← m.bot_eq_zero, eq_bot_iff, m.bot_eq_zero, ← m.toSyn.map_zero] rw [degree_le_iff] rw [totalDegree_eq_zero_iff] apply forall_congr' intro d apply imp_congr (rfl.to_iff) rw [map_zero, ← m.bot_eq_zero, ← eq_bot_iff, m.bot_eq_zero] simp only [EmbeddingLike.map_eq_zero_iff] exact Finsupp.ext_iff @[simp]
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
degree_eq_zero_iff_totalDegree_eq_zero
null
degree_C (r : R) : m.degree (C r) = 0 := by rw [degree_eq_zero_iff_totalDegree_eq_zero, totalDegree_C]
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
degree_C
null
eq_C_of_degree_eq_zero {f : MvPolynomial σ R} (hf : m.degree f = 0) : f = C (m.leadingCoeff f) := by ext d simp only [leadingCoeff, hf] classical by_cases hd : d = 0 · simp [hd] · rw [coeff_C, if_neg (Ne.symm hd)] apply coeff_eq_zero_of_lt (m := m) rw [hf, map_zero, lt_iff_le_and_ne, ne_eq, eq_comm, EmbeddingLike.map_eq_zero_iff] exact ⟨bot_le, hd⟩
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
eq_C_of_degree_eq_zero
null
degree_eq_zero_iff {f : MvPolynomial σ R} : m.degree f = 0 ↔ f = C (m.leadingCoeff f) := ⟨MonomialOrder.eq_C_of_degree_eq_zero, fun h => by rw [h, MonomialOrder.degree_C]⟩
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
degree_eq_zero_iff
null
degree_add_le {f g : MvPolynomial σ R} : m.toSyn (m.degree (f + g)) ≤ m.toSyn (m.degree f) ⊔ m.toSyn (m.degree g) := by conv_rhs => rw [← m.toSyn.apply_symm_apply (_ ⊔ _)] rw [degree_le_iff] simp only [AddEquiv.apply_symm_apply, le_sup_iff] intro b hb by_cases hf : b ∈ f.support · left exact m.le_degree hf · right apply m.le_degree simp only [notMem_support_iff] at hf simpa only [mem_support_iff, coeff_add, hf, zero_add] using hb
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
degree_add_le
null
degree_sum_le {α : Type*} {s : Finset α} {f : α → MvPolynomial σ R} : (m.toSyn <| m.degree <| ∑ x ∈ s, f x) ≤ s.sup fun x ↦ (m.toSyn <| m.degree <| f x) := by induction s using Finset.cons_induction_on with | empty => simp | cons a s haA h => rw [Finset.sum_cons, Finset.sup_cons] exact le_trans m.degree_add_le (max_le_max le_rfl h)
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
degree_sum_le
null
degree_add_of_lt {f g : MvPolynomial σ R} (h : m.degree g ≺[m] m.degree f) : m.degree (f + g) = m.degree f := by apply m.toSyn.injective apply le_antisymm · apply le_trans degree_add_le simp only [sup_le_iff, le_refl, true_and, le_of_lt h] · apply le_degree rw [mem_support_iff, coeff_add, m.coeff_eq_zero_of_lt h, add_zero, ← leadingCoeff, leadingCoeff_ne_zero_iff] intro hf rw [← not_le, hf] at h apply h simp only [degree_zero, map_zero] apply bot_le
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
degree_add_of_lt
null
degree_add_eq_right_of_lt {f g : MvPolynomial σ R} (h : m.degree f ≺[m] m.degree g) : m.degree (f + g) = m.degree g := by rw [add_comm] exact degree_add_of_lt h
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
degree_add_eq_right_of_lt
null
leadingCoeff_add_of_lt {f g : MvPolynomial σ R} (h : m.degree g ≺[m] m.degree f) : m.leadingCoeff (f + g) = m.leadingCoeff f := by simp only [leadingCoeff, m.degree_add_of_lt h, coeff_add, coeff_eq_zero_of_lt h, add_zero]
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
leadingCoeff_add_of_lt
null
Monic.add_of_lt {f g : MvPolynomial σ R} (hf : m.Monic f) (h : m.degree g ≺[m] m.degree f) : m.Monic (f + g) := by simp only [Monic, leadingCoeff_add_of_lt h, hf.leadingCoeff_eq_one]
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
Monic.add_of_lt
null
degree_add_of_ne {f g : MvPolynomial σ R} (h : m.degree f ≠ m.degree g) : m.toSyn (m.degree (f + g)) = m.toSyn (m.degree f) ⊔ m.toSyn (m.degree g) := by by_cases h' : m.degree g ≺[m] m.degree f · simp [degree_add_of_lt h', le_of_lt h'] · rw [not_lt, le_iff_eq_or_lt, Classical.or_iff_not_imp_left, EmbeddingLike.apply_eq_iff_eq] at h' rw [add_comm, degree_add_of_lt (h' h), right_eq_sup] simp only [le_of_lt (h' h)]
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
degree_add_of_ne
null
degree_mul_le {f g : MvPolynomial σ R} : m.degree (f * g) ≼[m] m.degree f + m.degree g := by classical rw [degree_le_iff] intro c rw [← not_lt, mem_support_iff, not_imp_not] intro hc rw [coeff_mul] apply Finset.sum_eq_zero rintro ⟨d, e⟩ hde simp only [Finset.mem_antidiagonal] at hde dsimp only by_cases hd : m.degree f ≺[m] d · rw [m.coeff_eq_zero_of_lt hd, zero_mul] · suffices m.degree g ≺[m] e by rw [m.coeff_eq_zero_of_lt this, mul_zero] simp only [not_lt] at hd apply lt_of_add_lt_add_left (a := m.toSyn d) simp only [← map_add, hde] apply lt_of_le_of_lt _ hc simp only [map_add] exact add_le_add_right hd _
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
degree_mul_le
null
coeff_mul_of_add_of_degree_le {f g : MvPolynomial σ R} {a b : σ →₀ ℕ} (ha : m.degree f ≼[m] a) (hb : m.degree g ≼[m] b) : (f * g).coeff (a + b) = f.coeff a * g.coeff b := by classical rw [coeff_mul, Finset.sum_eq_single (a,b)] · rintro ⟨c, d⟩ hcd h simp only [Finset.mem_antidiagonal] at hcd by_cases hf : m.degree f ≺[m] c · rw [m.coeff_eq_zero_of_lt hf, zero_mul] · suffices m.degree g ≺[m] d by rw [coeff_eq_zero_of_lt this, mul_zero] rw [not_lt] at hf rw [← not_le] intro hf' apply h suffices c = a by simpa [Prod.mk.injEq, this] using hcd apply m.toSyn.injective apply le_antisymm (le_trans hf ha) apply le_of_add_le_add_right (a := m.toSyn b) rw [← map_add, ← hcd, map_add] simp only [add_le_add_iff_left] exact le_trans hf' hb · simp
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
coeff_mul_of_add_of_degree_le
Multiplicativity of leading coefficients
coeff_mul_of_degree_add {f g : MvPolynomial σ R} : (f * g).coeff (m.degree f + m.degree g) = m.leadingCoeff f * m.leadingCoeff g := coeff_mul_of_add_of_degree_le (le_of_eq rfl) (le_of_eq rfl)
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
coeff_mul_of_degree_add
Multiplicativity of leading coefficients
degree_mul_of_mul_leadingCoeff_ne_zero {f g : MvPolynomial σ R} (hfg : m.leadingCoeff f * m.leadingCoeff g ≠ 0) : m.degree (f * g) = m.degree f + m.degree g := by apply m.toSyn.injective apply le_antisymm degree_mul_le apply le_degree rw [mem_support_iff, coeff_mul_of_degree_add] exact hfg
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
degree_mul_of_mul_leadingCoeff_ne_zero
Monomial degree of product
leadingCoeff_mul_of_mul_leadingCoeff_ne_zero {f g : MvPolynomial σ R} (hfg : m.leadingCoeff f * m.leadingCoeff g ≠ 0) : m.leadingCoeff (f * g) = m.leadingCoeff f * m.leadingCoeff g := by rw [leadingCoeff, ← coeff_mul_of_degree_add, degree_mul_of_mul_leadingCoeff_ne_zero hfg]
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
leadingCoeff_mul_of_mul_leadingCoeff_ne_zero
Multiplicativity of leading coefficients
degree_mul_of_isRegular_left {f g : MvPolynomial σ R} (hf : IsRegular (m.leadingCoeff f)) (hg : g ≠ 0) : m.degree (f * g) = m.degree f + m.degree g := by apply degree_mul_of_mul_leadingCoeff_ne_zero simp only [ne_eq, hf, IsRegular.left, IsLeftRegular.mul_left_eq_zero_iff, leadingCoeff_eq_zero_iff] exact hg
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
degree_mul_of_isRegular_left
Monomial degree of product
leadingCoeff_mul_of_isRegular_left {f g : MvPolynomial σ R} (hf : IsRegular (m.leadingCoeff f)) (hg : g ≠ 0) : m.leadingCoeff (f * g) = m.leadingCoeff f * m.leadingCoeff g := by simp only [leadingCoeff, degree_mul_of_isRegular_left hf hg, coeff_mul_of_degree_add]
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
leadingCoeff_mul_of_isRegular_left
Multiplicativity of leading coefficients
degree_mul_of_isRegular_right {f g : MvPolynomial σ R} (hf : f ≠ 0) (hg : IsRegular (m.leadingCoeff g)) : m.degree (f * g) = m.degree f + m.degree g := by rw [mul_comm, m.degree_mul_of_isRegular_left hg hf, add_comm]
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
degree_mul_of_isRegular_right
Monomial degree of product
leadingCoeff_mul_of_isRegular_right {f g : MvPolynomial σ R} (hf : f ≠ 0) (hg : IsRegular (m.leadingCoeff g)) : m.leadingCoeff (f * g) = m.leadingCoeff f * m.leadingCoeff g := by simp only [leadingCoeff, degree_mul_of_isRegular_right hf hg, coeff_mul_of_degree_add]
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
leadingCoeff_mul_of_isRegular_right
Multiplicativity of leading coefficients
Monic.mul {f g : MvPolynomial σ R} (hf : m.Monic f) (hg : m.Monic g) : m.Monic (f * g) := by nontriviality R suffices m.leadingCoeff f * m.leadingCoeff g = 1 by rw [Monic, MonomialOrder.leadingCoeff, degree_mul_of_mul_leadingCoeff_ne_zero, coeff_mul_of_degree_add, this] rw [this] exact one_ne_zero rw [hf.leadingCoeff_eq_one, hg.leadingCoeff_eq_one, one_mul]
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
Monic.mul
null
degree_mul [IsCancelMulZero R] {f g : MvPolynomial σ R} (hf : f ≠ 0) (hg : g ≠ 0) : m.degree (f * g) = m.degree f + m.degree g := degree_mul_of_isRegular_left (isRegular_of_ne_zero (leadingCoeff_ne_zero_iff.mpr hf)) hg
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
degree_mul
Monomial degree of product
leadingCoeff_mul [IsCancelMulZero R] {f g : MvPolynomial σ R} (hf : f ≠ 0) (hg : g ≠ 0) : m.leadingCoeff (f * g) = m.leadingCoeff f * m.leadingCoeff g := by rw [leadingCoeff, degree_mul hf hg, ← coeff_mul_of_degree_add]
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
leadingCoeff_mul
Multiplicativity of leading coefficients
degree_pow_le {f : MvPolynomial σ R} (n : ℕ) : m.degree (f ^ n) ≼[m] n • (m.degree f) := by induction n with | zero => simp [m.degree_one] | succ n hrec => simp only [pow_add, pow_one, add_smul, one_smul] apply le_trans m.degree_mul_le simp only [map_add, add_le_add_iff_right] exact hrec
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
degree_pow_le
Monomial degree of powers
coeff_pow_nsmul_degree (f : MvPolynomial σ R) (n : ℕ) : (f ^ n).coeff (n • m.degree f) = m.leadingCoeff f ^ n := by induction n with | zero => simp | succ n hrec => simp only [add_smul, one_smul, pow_add, pow_one] rw [m.coeff_mul_of_add_of_degree_le (m.degree_pow_le _) le_rfl, hrec, leadingCoeff]
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
coeff_pow_nsmul_degree
null
degree_pow_of_pow_leadingCoeff_ne_zero {f : MvPolynomial σ R} {n : ℕ} (hf : m.leadingCoeff f ^ n ≠ 0) : m.degree (f ^ n) = n • m.degree f := by apply m.toSyn.injective apply le_antisymm (m.degree_pow_le n) apply le_degree rw [mem_support_iff, coeff_pow_nsmul_degree] exact hf
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
degree_pow_of_pow_leadingCoeff_ne_zero
Monomial degree of powers
leadingCoeff_pow_of_pow_leadingCoeff_ne_zero {f : MvPolynomial σ R} {n : ℕ} (hf : m.leadingCoeff f ^ n ≠ 0) : m.leadingCoeff (f ^ n) = m.leadingCoeff f ^ n := by rw [leadingCoeff, degree_pow_of_pow_leadingCoeff_ne_zero hf, coeff_pow_nsmul_degree]
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
leadingCoeff_pow_of_pow_leadingCoeff_ne_zero
Leading coefficient of powers
protected Monic.pow {f : MvPolynomial σ R} {n : ℕ} (hf : m.Monic f) : m.Monic (f ^ n) := by nontriviality R rw [Monic, leadingCoeff_pow_of_pow_leadingCoeff_ne_zero, hf.leadingCoeff_eq_one, one_pow] rw [hf.leadingCoeff_eq_one, one_pow] exact one_ne_zero
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
Monic.pow
null
degree_pow [IsReduced R] (f : MvPolynomial σ R) (n : ℕ) : m.degree (f ^ n) = n • m.degree f := by by_cases hf : f = 0 · rw [hf, degree_zero, smul_zero] by_cases hn : n = 0 · rw [hn, pow_zero, degree_one] · rw [zero_pow hn, degree_zero] nontriviality R apply degree_pow_of_pow_leadingCoeff_ne_zero apply IsReduced.pow_ne_zero rw [leadingCoeff_ne_zero_iff] exact hf
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
degree_pow
Monomial degree of powers (in a reduced ring)
leadingCoeff_pow [IsReduced R] (f : MvPolynomial σ R) (n : ℕ) : m.leadingCoeff (f ^ n) = m.leadingCoeff f ^ n := by rw [leadingCoeff, degree_pow, coeff_pow_nsmul_degree]
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
leadingCoeff_pow
Leading coefficient of powers (in a reduced ring)
degree_smul_le {r : R} {f : MvPolynomial σ R} : m.degree (r • f) ≼[m] m.degree f := by rw [smul_eq_C_mul] apply le_of_le_of_eq degree_mul_le simp
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
degree_smul_le
null
degree_smul {r : R} (hr : IsRegular r) {f : MvPolynomial σ R} : m.degree (r • f) = m.degree f := by by_cases hf : f = 0 · simp [hf] apply m.toSyn.injective apply le_antisymm degree_smul_le apply le_degree simp only [mem_support_iff, smul_eq_C_mul] rw [← zero_add (degree m f), ← degree_C r, coeff_mul_of_degree_add] simp [leadingCoeff, hr.left.mul_left_eq_zero_iff, hf]
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
degree_smul
null
degree_prod_le {ι : Type*} {P : ι → MvPolynomial σ R} {s : Finset ι} : m.degree (∏ i ∈ s, P i) ≼[m] ∑ i ∈ s, m.degree (P i) := by classical induction s using Finset.induction_on with | empty => simp only [Finset.prod_empty, Finset.sum_empty] rw [← C_1, m.degree_C, map_zero] | insert a s has hrec => rw [Finset.prod_insert has, Finset.sum_insert has] apply le_trans degree_mul_le simp only [map_add, add_le_add_iff_left, hrec]
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
degree_prod_le
null
coeff_prod_sum_degree {ι : Type*} (P : ι → MvPolynomial σ R) (s : Finset ι) : coeff (∑ i ∈ s, m.degree (P i)) (∏ i ∈ s, P i) = ∏ i ∈ s, m.leadingCoeff (P i) := by classical induction s using Finset.induction_on with | empty => simp | insert a s has hrec => simp only [Finset.prod_insert has, Finset.sum_insert has] rw [coeff_mul_of_add_of_degree_le (le_of_eq rfl) degree_prod_le] exact congr_arg₂ _ rfl hrec
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
coeff_prod_sum_degree
null
degree_prod_of_regular {ι : Type*} {P : ι → MvPolynomial σ R} {s : Finset ι} (H : ∀ i ∈ s, IsRegular (m.leadingCoeff (P i))) : m.degree (∏ i ∈ s, P i) = ∑ i ∈ s, m.degree (P i) := by cases subsingleton_or_nontrivial R with | inl _ => simp [Subsingleton.elim _ (0 : MvPolynomial σ R)] | inr _ => apply m.toSyn.injective refine le_antisymm degree_prod_le (m.le_degree ?_) rw [mem_support_iff, m.coeff_prod_sum_degree] exact (IsRegular.prod H).ne_zero
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
degree_prod_of_regular
null
degree_prod [IsCancelMulZero R] {ι : Type*} {P : ι → MvPolynomial σ R} {s : Finset ι} (H : ∀ i ∈ s, P i ≠ 0) : m.degree (∏ i ∈ s, P i) = ∑ i ∈ s, m.degree (P i) := by apply degree_prod_of_regular intro i hi apply isRegular_of_ne_zero rw [leadingCoeff_ne_zero_iff] exact H i hi
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
degree_prod
null
leadingCoeff_prod_of_regular {ι : Type*} {P : ι → MvPolynomial σ R} {s : Finset ι} (H : ∀ i ∈ s, IsRegular (m.leadingCoeff (P i))) : m.leadingCoeff (∏ i ∈ s, P i) = ∏ i ∈ s, m.leadingCoeff (P i) := by simp only [leadingCoeff, degree_prod_of_regular H, coeff_prod_sum_degree]
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
leadingCoeff_prod_of_regular
null
protected Monic.prod {ι : Type*} {P : ι → MvPolynomial σ R} {s : Finset ι} (H : ∀ i ∈ s, m.Monic (P i)) : m.Monic (∏ i ∈ s, P i) := by rw [Monic, leadingCoeff_prod_of_regular] · exact Finset.prod_eq_one H · intro i hi rw [(H i hi).leadingCoeff_eq_one] exact isRegular_one
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
Monic.prod
A product of monic polynomials is monic
@[simp] degree_neg {f : MvPolynomial σ R} : m.degree (-f) = m.degree f := by unfold degree rw [support_neg] @[simp]
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
degree_neg
null
leadingCoeff_neg {f : MvPolynomial σ R} : m.leadingCoeff (-f) = - m.leadingCoeff f := by simp only [leadingCoeff, degree_neg, coeff_neg]
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
leadingCoeff_neg
null
degree_sub_le {f g : MvPolynomial σ R} : m.toSyn (m.degree (f - g)) ≤ m.toSyn (m.degree f) ⊔ m.toSyn (m.degree g) := by rw [sub_eq_add_neg] apply le_of_le_of_eq m.degree_add_le rw [degree_neg]
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
degree_sub_le
null
degree_sub_of_lt {f g : MvPolynomial σ R} (h : m.degree g ≺[m] m.degree f) : m.degree (f - g) = m.degree f := by rw [sub_eq_add_neg] apply degree_add_of_lt simp only [degree_neg, h]
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
degree_sub_of_lt
null
leadingCoeff_sub_of_lt {f g : MvPolynomial σ R} (h : m.degree g ≺[m] m.degree f) : m.leadingCoeff (f - g) = m.leadingCoeff f := by rw [sub_eq_add_neg] apply leadingCoeff_add_of_lt simp only [degree_neg, h]
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
leadingCoeff_sub_of_lt
null
isUnit_leadingCoeff {f : MvPolynomial σ R} : IsUnit (m.leadingCoeff f) ↔ f ≠ 0 := by simp only [isUnit_iff_ne_zero, ne_eq, leadingCoeff_eq_zero_iff]
theorem
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
isUnit_leadingCoeff
null
degree_X_add_C [Nontrivial R] {ι : Type*} (m : MonomialOrder ι) (i : ι) (r : R) : m.degree (X i + C r) = single i 1 := by rw [degree_add_of_lt, degree_X] simp only [degree_C, map_zero, degree_X] rw [← bot_eq_zero, bot_lt_iff_ne_bot, bot_eq_zero, ← map_zero m.toSyn] simp
lemma
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
degree_X_add_C
null
degree_X_sub_C [Nontrivial R] {ι : Type*} (m : MonomialOrder ι) (i : ι) (r : R) : m.degree (X i - C r) = single i 1 := by rw [sub_eq_add_neg, ← map_neg, degree_X_add_C]
lemma
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
degree_X_sub_C
null
monic_X_add_C {ι : Type*} (m : MonomialOrder ι) (i : ι) (r : R) : m.Monic (X i + C r) := by nontriviality R apply monic_X.add_of_lt simp [degree_C, degree_X, ← not_le, ← eq_zero_iff]
lemma
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
monic_X_add_C
null
monic_X_sub_C {ι : Type*} (m : MonomialOrder ι) (i : ι) (r : R) : m.Monic (X i - C r) := by rw [sub_eq_add_neg, ← map_neg] apply monic_X_add_C
lemma
RingTheory
[ "Mathlib.Data.Finsupp.Lex", "Mathlib.Data.Finsupp.MonomialOrder", "Mathlib.Data.Finsupp.WellFounded", "Mathlib.Data.List.TFAE", "Mathlib.RingTheory.MvPolynomial.Homogeneous", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean
monic_X_sub_C
null
aeval_map_algebraMap (x : σ → B) (p : MvPolynomial σ R) : aeval x (map (algebraMap R A) p) = aeval x p := by rw [aeval_def, aeval_def, eval₂_map, IsScalarTower.algebraMap_eq R A B]
theorem
RingTheory
[ "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.MvPolynomial.Eval" ]
Mathlib/RingTheory/MvPolynomial/Tower.lean
aeval_map_algebraMap
null
aeval_algebraMap_apply (x : σ → A) (p : MvPolynomial σ R) : aeval (algebraMap A B ∘ x) p = algebraMap A B (MvPolynomial.aeval x p) := by rw [aeval_def, aeval_def, ← coe_eval₂Hom, ← coe_eval₂Hom, map_eval₂Hom, ← IsScalarTower.algebraMap_eq, Function.comp_def]
theorem
RingTheory
[ "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.MvPolynomial.Eval" ]
Mathlib/RingTheory/MvPolynomial/Tower.lean
aeval_algebraMap_apply
null
aeval_algebraMap_eq_zero_iff [NoZeroSMulDivisors A B] [Nontrivial B] (x : σ → A) (p : MvPolynomial σ R) : aeval (algebraMap A B ∘ x) p = 0 ↔ aeval x p = 0 := by rw [aeval_algebraMap_apply, Algebra.algebraMap_eq_smul_one, smul_eq_zero, iff_false_intro (one_ne_zero' B), or_false]
theorem
RingTheory
[ "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.MvPolynomial.Eval" ]
Mathlib/RingTheory/MvPolynomial/Tower.lean
aeval_algebraMap_eq_zero_iff
null
aeval_algebraMap_eq_zero_iff_of_injective {x : σ → A} {p : MvPolynomial σ R} (h : Function.Injective (algebraMap A B)) : aeval (algebraMap A B ∘ x) p = 0 ↔ aeval x p = 0 := by rw [aeval_algebraMap_apply, ← (algebraMap A B).map_zero, h.eq_iff]
theorem
RingTheory
[ "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.MvPolynomial.Eval" ]
Mathlib/RingTheory/MvPolynomial/Tower.lean
aeval_algebraMap_eq_zero_iff_of_injective
null
@[simp] mvPolynomial_aeval_coe (S : Subalgebra R A) (x : σ → S) (p : MvPolynomial σ R) : aeval (fun i => (x i : A)) p = aeval x p := by convert aeval_algebraMap_apply A x p
theorem
RingTheory
[ "Mathlib.Algebra.Algebra.Subalgebra.Tower", "Mathlib.Algebra.MvPolynomial.Eval" ]
Mathlib/RingTheory/MvPolynomial/Tower.lean
mvPolynomial_aeval_coe
null
weightedTotalDegree' (w : σ → M) (p : MvPolynomial σ R) : WithBot M := p.support.sup fun s => weight w s
def
RingTheory
[ "Mathlib.Algebra.BigOperators.Finprod", "Mathlib.Algebra.DirectSum.Decomposition", "Mathlib.Algebra.GradedMonoid", "Mathlib.Algebra.MvPolynomial.Basic", "Mathlib.Algebra.Order.Monoid.Canonical.Defs", "Mathlib.Data.Finsupp.Weight", "Mathlib.RingTheory.GradedAlgebra.Basic" ]
Mathlib/RingTheory/MvPolynomial/WeightedHomogeneous.lean
weightedTotalDegree'
The weighted total degree of a multivariate polynomial, taking values in `WithBot M`.
weightedTotalDegree'_eq_bot_iff (w : σ → M) (p : MvPolynomial σ R) : weightedTotalDegree' w p = ⊥ ↔ p = 0 := by simp only [weightedTotalDegree', Finset.sup_eq_bot_iff, mem_support_iff, WithBot.coe_ne_bot, MvPolynomial.eq_zero_iff] exact forall_congr' fun _ => Classical.not_not
theorem
RingTheory
[ "Mathlib.Algebra.BigOperators.Finprod", "Mathlib.Algebra.DirectSum.Decomposition", "Mathlib.Algebra.GradedMonoid", "Mathlib.Algebra.MvPolynomial.Basic", "Mathlib.Algebra.Order.Monoid.Canonical.Defs", "Mathlib.Data.Finsupp.Weight", "Mathlib.RingTheory.GradedAlgebra.Basic" ]
Mathlib/RingTheory/MvPolynomial/WeightedHomogeneous.lean
weightedTotalDegree'_eq_bot_iff
The `weightedTotalDegree'` of a polynomial `p` is `⊥` if and only if `p = 0`.
weightedTotalDegree'_zero (w : σ → M) : weightedTotalDegree' w (0 : MvPolynomial σ R) = ⊥ := by simp only [weightedTotalDegree', support_zero, Finset.sup_empty]
theorem
RingTheory
[ "Mathlib.Algebra.BigOperators.Finprod", "Mathlib.Algebra.DirectSum.Decomposition", "Mathlib.Algebra.GradedMonoid", "Mathlib.Algebra.MvPolynomial.Basic", "Mathlib.Algebra.Order.Monoid.Canonical.Defs", "Mathlib.Data.Finsupp.Weight", "Mathlib.RingTheory.GradedAlgebra.Basic" ]
Mathlib/RingTheory/MvPolynomial/WeightedHomogeneous.lean
weightedTotalDegree'_zero
The `weightedTotalDegree'` of the zero polynomial is `⊥`.
weightedTotalDegree (w : σ → M) (p : MvPolynomial σ R) : M := p.support.sup fun s => weight w s
def
RingTheory
[ "Mathlib.Algebra.BigOperators.Finprod", "Mathlib.Algebra.DirectSum.Decomposition", "Mathlib.Algebra.GradedMonoid", "Mathlib.Algebra.MvPolynomial.Basic", "Mathlib.Algebra.Order.Monoid.Canonical.Defs", "Mathlib.Data.Finsupp.Weight", "Mathlib.RingTheory.GradedAlgebra.Basic" ]
Mathlib/RingTheory/MvPolynomial/WeightedHomogeneous.lean
weightedTotalDegree
When `M` has a `⊥` element, we can define the weighted total degree of a multivariate polynomial as a function taking values in `M`.
weightedTotalDegree_coe (w : σ → M) (p : MvPolynomial σ R) (hp : p ≠ 0) : weightedTotalDegree' w p = ↑(weightedTotalDegree w p) := by rw [Ne, ← weightedTotalDegree'_eq_bot_iff w p, ← Ne, WithBot.ne_bot_iff_exists] at hp obtain ⟨m, hm⟩ := hp apply le_antisymm · simp only [weightedTotalDegree, weightedTotalDegree', Finset.sup_le_iff, WithBot.coe_le_coe] intro b exact Finset.le_sup · simp only [weightedTotalDegree] have hm' : weightedTotalDegree' w p ≤ m := le_of_eq hm.symm rw [← hm] simpa [weightedTotalDegree'] using hm'
theorem
RingTheory
[ "Mathlib.Algebra.BigOperators.Finprod", "Mathlib.Algebra.DirectSum.Decomposition", "Mathlib.Algebra.GradedMonoid", "Mathlib.Algebra.MvPolynomial.Basic", "Mathlib.Algebra.Order.Monoid.Canonical.Defs", "Mathlib.Data.Finsupp.Weight", "Mathlib.RingTheory.GradedAlgebra.Basic" ]
Mathlib/RingTheory/MvPolynomial/WeightedHomogeneous.lean
weightedTotalDegree_coe
This lemma relates `weightedTotalDegree` and `weightedTotalDegree'`.
weightedTotalDegree_zero (w : σ → M) : weightedTotalDegree w (0 : MvPolynomial σ R) = ⊥ := by simp only [weightedTotalDegree, support_zero, Finset.sup_empty]
theorem
RingTheory
[ "Mathlib.Algebra.BigOperators.Finprod", "Mathlib.Algebra.DirectSum.Decomposition", "Mathlib.Algebra.GradedMonoid", "Mathlib.Algebra.MvPolynomial.Basic", "Mathlib.Algebra.Order.Monoid.Canonical.Defs", "Mathlib.Data.Finsupp.Weight", "Mathlib.RingTheory.GradedAlgebra.Basic" ]
Mathlib/RingTheory/MvPolynomial/WeightedHomogeneous.lean
weightedTotalDegree_zero
The `weightedTotalDegree` of the zero polynomial is `⊥`.
le_weightedTotalDegree (w : σ → M) {φ : MvPolynomial σ R} {d : σ →₀ ℕ} (hd : d ∈ φ.support) : weight w d ≤ φ.weightedTotalDegree w := le_sup hd
theorem
RingTheory
[ "Mathlib.Algebra.BigOperators.Finprod", "Mathlib.Algebra.DirectSum.Decomposition", "Mathlib.Algebra.GradedMonoid", "Mathlib.Algebra.MvPolynomial.Basic", "Mathlib.Algebra.Order.Monoid.Canonical.Defs", "Mathlib.Data.Finsupp.Weight", "Mathlib.RingTheory.GradedAlgebra.Basic" ]
Mathlib/RingTheory/MvPolynomial/WeightedHomogeneous.lean
le_weightedTotalDegree
null
IsWeightedHomogeneous (w : σ → M) (φ : MvPolynomial σ R) (m : M) : Prop := ∀ ⦃d⦄, coeff d φ ≠ 0 → weight w d = m variable (R)
def
RingTheory
[ "Mathlib.Algebra.BigOperators.Finprod", "Mathlib.Algebra.DirectSum.Decomposition", "Mathlib.Algebra.GradedMonoid", "Mathlib.Algebra.MvPolynomial.Basic", "Mathlib.Algebra.Order.Monoid.Canonical.Defs", "Mathlib.Data.Finsupp.Weight", "Mathlib.RingTheory.GradedAlgebra.Basic" ]
Mathlib/RingTheory/MvPolynomial/WeightedHomogeneous.lean
IsWeightedHomogeneous
A multivariate polynomial `φ` is weighted homogeneous of weighted degree `m` if all monomials occurring in `φ` have weighted degree `m`.
weightedHomogeneousSubmodule (w : σ → M) (m : M) : Submodule R (MvPolynomial σ R) where carrier := { x | x.IsWeightedHomogeneous w m } smul_mem' r a ha c hc := by rw [coeff_smul] at hc exact ha (right_ne_zero_of_mul hc) zero_mem' _ hd := False.elim (hd <| coeff_zero _) add_mem' {a} {b} ha hb c hc := by rw [coeff_add] at hc obtain h | h : coeff c a ≠ 0 ∨ coeff c b ≠ 0 := by contrapose! hc simp only [hc, add_zero] · exact ha h · exact hb h @[simp]
def
RingTheory
[ "Mathlib.Algebra.BigOperators.Finprod", "Mathlib.Algebra.DirectSum.Decomposition", "Mathlib.Algebra.GradedMonoid", "Mathlib.Algebra.MvPolynomial.Basic", "Mathlib.Algebra.Order.Monoid.Canonical.Defs", "Mathlib.Data.Finsupp.Weight", "Mathlib.RingTheory.GradedAlgebra.Basic" ]
Mathlib/RingTheory/MvPolynomial/WeightedHomogeneous.lean
weightedHomogeneousSubmodule
The submodule of homogeneous `MvPolynomial`s of degree `n`.
mem_weightedHomogeneousSubmodule (w : σ → M) (m : M) (p : MvPolynomial σ R) : p ∈ weightedHomogeneousSubmodule R w m ↔ p.IsWeightedHomogeneous w m := Iff.rfl
theorem
RingTheory
[ "Mathlib.Algebra.BigOperators.Finprod", "Mathlib.Algebra.DirectSum.Decomposition", "Mathlib.Algebra.GradedMonoid", "Mathlib.Algebra.MvPolynomial.Basic", "Mathlib.Algebra.Order.Monoid.Canonical.Defs", "Mathlib.Data.Finsupp.Weight", "Mathlib.RingTheory.GradedAlgebra.Basic" ]
Mathlib/RingTheory/MvPolynomial/WeightedHomogeneous.lean
mem_weightedHomogeneousSubmodule
null
weightedHomogeneousSubmodule_eq_finsupp_supported (w : σ → M) (m : M) : weightedHomogeneousSubmodule R w m = Finsupp.supported R R { d | weight w d = m } := by ext x rw [mem_supported, Set.subset_def] simp only [Finsupp.mem_support_iff, mem_coe] rfl variable {R}
theorem
RingTheory
[ "Mathlib.Algebra.BigOperators.Finprod", "Mathlib.Algebra.DirectSum.Decomposition", "Mathlib.Algebra.GradedMonoid", "Mathlib.Algebra.MvPolynomial.Basic", "Mathlib.Algebra.Order.Monoid.Canonical.Defs", "Mathlib.Data.Finsupp.Weight", "Mathlib.RingTheory.GradedAlgebra.Basic" ]
Mathlib/RingTheory/MvPolynomial/WeightedHomogeneous.lean
weightedHomogeneousSubmodule_eq_finsupp_supported
The submodule `weightedHomogeneousSubmodule R w m` of homogeneous `MvPolynomial`s of degree `n` is equal to the `R`-submodule of all `p : (σ →₀ ℕ) →₀ R` such that `p.support ⊆ {d | weight w d = m}`. While equal, the former has a convenient definitional reduction.
weightedHomogeneousSubmodule_mul (w : σ → M) (m n : M) : weightedHomogeneousSubmodule R w m * weightedHomogeneousSubmodule R w n ≤ weightedHomogeneousSubmodule R w (m + n) := by classical rw [Submodule.mul_le] intro φ hφ ψ hψ c hc rw [coeff_mul] at hc obtain ⟨⟨d, e⟩, hde, H⟩ := Finset.exists_ne_zero_of_sum_ne_zero hc have aux : coeff d φ ≠ 0 ∧ coeff e ψ ≠ 0 := by contrapose! H by_cases h : coeff d φ = 0 <;> simp_all only [Ne, not_false_iff, zero_mul, mul_zero] rw [← mem_antidiagonal.mp hde, ← hφ aux.1, ← hψ aux.2, map_add]
theorem
RingTheory
[ "Mathlib.Algebra.BigOperators.Finprod", "Mathlib.Algebra.DirectSum.Decomposition", "Mathlib.Algebra.GradedMonoid", "Mathlib.Algebra.MvPolynomial.Basic", "Mathlib.Algebra.Order.Monoid.Canonical.Defs", "Mathlib.Data.Finsupp.Weight", "Mathlib.RingTheory.GradedAlgebra.Basic" ]
Mathlib/RingTheory/MvPolynomial/WeightedHomogeneous.lean
weightedHomogeneousSubmodule_mul
The submodule generated by products `Pm * Pn` of weighted homogeneous polynomials of degrees `m` and `n` is contained in the submodule of weighted homogeneous polynomials of degree `m + n`.
isWeightedHomogeneous_monomial (w : σ → M) (d : σ →₀ ℕ) (r : R) {m : M} (hm : weight w d = m) : IsWeightedHomogeneous w (monomial d r) m := by classical intro c hc rw [coeff_monomial] at hc split_ifs at hc with h · subst c exact hm · contradiction
theorem
RingTheory
[ "Mathlib.Algebra.BigOperators.Finprod", "Mathlib.Algebra.DirectSum.Decomposition", "Mathlib.Algebra.GradedMonoid", "Mathlib.Algebra.MvPolynomial.Basic", "Mathlib.Algebra.Order.Monoid.Canonical.Defs", "Mathlib.Data.Finsupp.Weight", "Mathlib.RingTheory.GradedAlgebra.Basic" ]
Mathlib/RingTheory/MvPolynomial/WeightedHomogeneous.lean
isWeightedHomogeneous_monomial
Monomials are weighted homogeneous.
isWeightedHomogeneous_of_total_degree_zero [SemilatticeSup M] [OrderBot M] (w : σ → M) {p : MvPolynomial σ R} (hp : weightedTotalDegree w p = (⊥ : M)) : IsWeightedHomogeneous w p (⊥ : M) := by intro d hd have h := weightedTotalDegree_coe w p (MvPolynomial.ne_zero_iff.mpr ⟨d, hd⟩) simp only [weightedTotalDegree', hp] at h rw [eq_bot_iff, ← WithBot.coe_le_coe, ← h] apply Finset.le_sup (mem_support_iff.mpr hd)
theorem
RingTheory
[ "Mathlib.Algebra.BigOperators.Finprod", "Mathlib.Algebra.DirectSum.Decomposition", "Mathlib.Algebra.GradedMonoid", "Mathlib.Algebra.MvPolynomial.Basic", "Mathlib.Algebra.Order.Monoid.Canonical.Defs", "Mathlib.Data.Finsupp.Weight", "Mathlib.RingTheory.GradedAlgebra.Basic" ]
Mathlib/RingTheory/MvPolynomial/WeightedHomogeneous.lean
isWeightedHomogeneous_of_total_degree_zero
A polynomial of weightedTotalDegree `⊥` is weighted_homogeneous of degree `⊥`.
isWeightedHomogeneous_C (w : σ → M) (r : R) : IsWeightedHomogeneous w (C r : MvPolynomial σ R) 0 := isWeightedHomogeneous_monomial _ _ _ (map_zero _) variable (R)
theorem
RingTheory
[ "Mathlib.Algebra.BigOperators.Finprod", "Mathlib.Algebra.DirectSum.Decomposition", "Mathlib.Algebra.GradedMonoid", "Mathlib.Algebra.MvPolynomial.Basic", "Mathlib.Algebra.Order.Monoid.Canonical.Defs", "Mathlib.Data.Finsupp.Weight", "Mathlib.RingTheory.GradedAlgebra.Basic" ]
Mathlib/RingTheory/MvPolynomial/WeightedHomogeneous.lean
isWeightedHomogeneous_C
Constant polynomials are weighted homogeneous of degree 0.
isWeightedHomogeneous_zero (w : σ → M) (m : M) : IsWeightedHomogeneous w (0 : MvPolynomial σ R) m := (weightedHomogeneousSubmodule R w m).zero_mem
theorem
RingTheory
[ "Mathlib.Algebra.BigOperators.Finprod", "Mathlib.Algebra.DirectSum.Decomposition", "Mathlib.Algebra.GradedMonoid", "Mathlib.Algebra.MvPolynomial.Basic", "Mathlib.Algebra.Order.Monoid.Canonical.Defs", "Mathlib.Data.Finsupp.Weight", "Mathlib.RingTheory.GradedAlgebra.Basic" ]
Mathlib/RingTheory/MvPolynomial/WeightedHomogeneous.lean
isWeightedHomogeneous_zero
0 is weighted homogeneous of any degree.
isWeightedHomogeneous_one (w : σ → M) : IsWeightedHomogeneous w (1 : MvPolynomial σ R) 0 := isWeightedHomogeneous_C _ _
theorem
RingTheory
[ "Mathlib.Algebra.BigOperators.Finprod", "Mathlib.Algebra.DirectSum.Decomposition", "Mathlib.Algebra.GradedMonoid", "Mathlib.Algebra.MvPolynomial.Basic", "Mathlib.Algebra.Order.Monoid.Canonical.Defs", "Mathlib.Data.Finsupp.Weight", "Mathlib.RingTheory.GradedAlgebra.Basic" ]
Mathlib/RingTheory/MvPolynomial/WeightedHomogeneous.lean
isWeightedHomogeneous_one
1 is weighted homogeneous of degree 0.
isWeightedHomogeneous_X (w : σ → M) (i : σ) : IsWeightedHomogeneous w (X i : MvPolynomial σ R) (w i) := by apply isWeightedHomogeneous_monomial simp only [weight, LinearMap.toAddMonoidHom_coe, linearCombination_single, one_nsmul]
theorem
RingTheory
[ "Mathlib.Algebra.BigOperators.Finprod", "Mathlib.Algebra.DirectSum.Decomposition", "Mathlib.Algebra.GradedMonoid", "Mathlib.Algebra.MvPolynomial.Basic", "Mathlib.Algebra.Order.Monoid.Canonical.Defs", "Mathlib.Data.Finsupp.Weight", "Mathlib.RingTheory.GradedAlgebra.Basic" ]
Mathlib/RingTheory/MvPolynomial/WeightedHomogeneous.lean
isWeightedHomogeneous_X
An indeterminate `i : σ` is weighted homogeneous of degree `w i`.
coeff_eq_zero {w : σ → M} (hφ : IsWeightedHomogeneous w φ n) (d : σ →₀ ℕ) (hd : weight w d ≠ n) : coeff d φ = 0 := by have aux := mt (@hφ d) hd rwa [Classical.not_not] at aux
theorem
RingTheory
[ "Mathlib.Algebra.BigOperators.Finprod", "Mathlib.Algebra.DirectSum.Decomposition", "Mathlib.Algebra.GradedMonoid", "Mathlib.Algebra.MvPolynomial.Basic", "Mathlib.Algebra.Order.Monoid.Canonical.Defs", "Mathlib.Data.Finsupp.Weight", "Mathlib.RingTheory.GradedAlgebra.Basic" ]
Mathlib/RingTheory/MvPolynomial/WeightedHomogeneous.lean
coeff_eq_zero
The weighted degree of a weighted homogeneous polynomial controls its support.
inj_right {w : σ → M} (hφ : φ ≠ 0) (hm : IsWeightedHomogeneous w φ m) (hn : IsWeightedHomogeneous w φ n) : m = n := by obtain ⟨d, hd⟩ : ∃ d, coeff d φ ≠ 0 := exists_coeff_ne_zero hφ rw [← hm hd, ← hn hd]
theorem
RingTheory
[ "Mathlib.Algebra.BigOperators.Finprod", "Mathlib.Algebra.DirectSum.Decomposition", "Mathlib.Algebra.GradedMonoid", "Mathlib.Algebra.MvPolynomial.Basic", "Mathlib.Algebra.Order.Monoid.Canonical.Defs", "Mathlib.Data.Finsupp.Weight", "Mathlib.RingTheory.GradedAlgebra.Basic" ]
Mathlib/RingTheory/MvPolynomial/WeightedHomogeneous.lean
inj_right
The weighted degree of a nonzero weighted homogeneous polynomial is well-defined.
add {w : σ → M} (hφ : IsWeightedHomogeneous w φ n) (hψ : IsWeightedHomogeneous w ψ n) : IsWeightedHomogeneous w (φ + ψ) n := (weightedHomogeneousSubmodule R w n).add_mem hφ hψ
theorem
RingTheory
[ "Mathlib.Algebra.BigOperators.Finprod", "Mathlib.Algebra.DirectSum.Decomposition", "Mathlib.Algebra.GradedMonoid", "Mathlib.Algebra.MvPolynomial.Basic", "Mathlib.Algebra.Order.Monoid.Canonical.Defs", "Mathlib.Data.Finsupp.Weight", "Mathlib.RingTheory.GradedAlgebra.Basic" ]
Mathlib/RingTheory/MvPolynomial/WeightedHomogeneous.lean
add
The sum of two weighted homogeneous polynomials of degree `n` is weighted homogeneous of weighted degree `n`.
sum {ι : Type*} (s : Finset ι) (φ : ι → MvPolynomial σ R) (n : M) {w : σ → M} (h : ∀ i ∈ s, IsWeightedHomogeneous w (φ i) n) : IsWeightedHomogeneous w (∑ i ∈ s, φ i) n := (weightedHomogeneousSubmodule R w n).sum_mem h
theorem
RingTheory
[ "Mathlib.Algebra.BigOperators.Finprod", "Mathlib.Algebra.DirectSum.Decomposition", "Mathlib.Algebra.GradedMonoid", "Mathlib.Algebra.MvPolynomial.Basic", "Mathlib.Algebra.Order.Monoid.Canonical.Defs", "Mathlib.Data.Finsupp.Weight", "Mathlib.RingTheory.GradedAlgebra.Basic" ]
Mathlib/RingTheory/MvPolynomial/WeightedHomogeneous.lean
sum
The sum of weighted homogeneous polynomials of degree `n` is weighted homogeneous of weighted degree `n`.
mul {w : σ → M} (hφ : IsWeightedHomogeneous w φ m) (hψ : IsWeightedHomogeneous w ψ n) : IsWeightedHomogeneous w (φ * ψ) (m + n) := weightedHomogeneousSubmodule_mul w m n <| Submodule.mul_mem_mul hφ hψ
theorem
RingTheory
[ "Mathlib.Algebra.BigOperators.Finprod", "Mathlib.Algebra.DirectSum.Decomposition", "Mathlib.Algebra.GradedMonoid", "Mathlib.Algebra.MvPolynomial.Basic", "Mathlib.Algebra.Order.Monoid.Canonical.Defs", "Mathlib.Data.Finsupp.Weight", "Mathlib.RingTheory.GradedAlgebra.Basic" ]
Mathlib/RingTheory/MvPolynomial/WeightedHomogeneous.lean
mul
The product of weighted homogeneous polynomials of weighted degrees `m` and `n` is weighted homogeneous of weighted degree `m + n`.