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Theorems · Theorem · field theory

Polynomial.coeff_mul

∀ {R : Type u} [inst : Semiring R] (p q : Polynomial R) (n : ℕ),
  (p * q).coeff n = ∑ x ∈ Finset.HasAntidiagonal.antidiagonal n, p.coeff x.1 * q.coeff x.2

Decomposes the coefficient of the product p * q as a sum over antidiagonal. A version which sums over range (n + 1) can be obtained by using Finset.Nat.sum_antidiagonal_eq_sum_range_succ.

Defined in
Mathlib.Algebra.Polynomial.Coeff
Cited by
29 results in Mathlib
Foundations
Depth 78 from the axioms · uses propext, Classical.choice, Quot.sound
Assumes
Semiring

Around this declaration

Dashed lines are statement dependencies; solid lines are citations in proofs.

Polynomial.mul_coeff_zero · cited by 37Polynomial.mul_coeff_zeroPolynomial.coeff_mul_X_pow · cited by 9Polynomial.coeff_mul_X_powIdeal.mem_map_C_iff · cited by 6Ideal.mem_map_C_iffPolynomial.coeff_mul_X_pow' · cited by 5Polynomial.coeff_mul_X_po…Polynomial.coeff_mul_degree_add_degree · cited by 5Polynomial.coeff_mul_degr…Polynomial.coe_mul · cited by 3Polynomial.coe_mulPolynomial.le_trailingDegree_mul · cited by 2Polynomial.le_trailingDeg…Polynomial.mul_scaleRoots · cited by 2Polynomial.mul_scaleRootsPolynomial.contentIdeal_mul_le_mul_contentIdeal · cited by 2Polynomial.contentIdeal_m…Polynomial.coeff_mul_add_eq_of_natDegree_le · cited by 2Polynomial.coeff_mul_add_…Nat.add_choose_eq · cited by 2Nat.add_choose_eqMvPolynomial.pderiv_inl_universalFactorizationMap_X · cited by 1MvPolynomial.pderiv_inl_u…MvPolynomial.pderiv_inr_universalFactorizationMap_X · cited by 1MvPolynomial.pderiv_inr_u…Polynomial.mul_coeff_one · cited by 1Polynomial.mul_coeff_onePolynomial.gaussNorm_mul_le · cited by 1Polynomial.gaussNorm_mul_…Semiring · cited by 13802SemiringPolynomial · cited by 5681PolynomialFinset.sum · cited by 5195Finset.sumPolynomial.coeff · cited by 1045Polynomial.coeffAddMonoidAlgebra · cited by 649AddMonoidAlgebraFinset.HasAntidiagonal.antidiagonal · cited by 218HasAntidiagonal.antidiago…Finset.HasAntidiagonal.mem_antidiagonal · cited by 51HasAntidiagonal.mem_antid…Polynomial.casesOn · cited by 15Polynomial.casesOnAddMonoidAlgebra.coeff_mul_antidiag · cited by 3AddMonoidAlgebra.coeff_mu…Polynomial.coeff_mulCITED BYCITES

Cites9

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Cited by29

Results whose statement or proof uses this declaration.