The binomial theorem for semirings
Content created by Fredrik Bakke, Jonathan Prieto-Cubides and Egbert Rijke.
Created on 2023-02-20.
Last modified on 2024-02-06.
module ring-theory.binomial-theorem-semirings where
Imports
open import elementary-number-theory.addition-natural-numbers open import elementary-number-theory.binomial-coefficients open import elementary-number-theory.distance-natural-numbers open import elementary-number-theory.inequality-natural-numbers open import elementary-number-theory.natural-numbers open import foundation.action-on-identifications-binary-functions open import foundation.action-on-identifications-functions open import foundation.homotopies open import foundation.identity-types open import foundation.universe-levels open import linear-algebra.vectors-on-semirings open import ring-theory.powers-of-elements-semirings open import ring-theory.semirings open import ring-theory.sums-semirings open import univalent-combinatorics.coproduct-types open import univalent-combinatorics.standard-finite-types
Idea
The binomial theorem in semirings asserts that for any two elements x and y
of a commutative ring R and any natural number n, if xy = yx holds then we
have
(x + y)ⁿ = ∑_{0 ≤ i < n+1} (n choose i) xⁱ yⁿ⁻ⁱ.
Definitions
Binomial sums
binomial-sum-Semiring : {l : Level} (R : Semiring l) (n : ℕ) (f : functional-vec-Semiring R (succ-ℕ n)) → type-Semiring R binomial-sum-Semiring R n f = sum-Semiring R (succ-ℕ n) ( λ i → mul-nat-scalar-Semiring R ( binomial-coefficient-Fin n i) ( f i))
Properties
Binomial sums of one and two elements
module _ {l : Level} (R : Semiring l) where binomial-sum-one-element-Semiring : (f : functional-vec-Semiring R 1) → binomial-sum-Semiring R 0 f ＝ head-functional-vec-Semiring R 0 f binomial-sum-one-element-Semiring f = ( sum-one-element-Semiring R ( λ i → mul-nat-scalar-Semiring R ( binomial-coefficient-Fin 0 i) ( f i))) ∙ ( left-unit-law-mul-nat-scalar-Semiring R ( head-functional-vec-Semiring R 0 f)) binomial-sum-two-elements-Semiring : (f : functional-vec-Semiring R 2) → binomial-sum-Semiring R 1 f ＝ add-Semiring R (f (zero-Fin 1)) (f (one-Fin 1)) binomial-sum-two-elements-Semiring f = sum-two-elements-Semiring R ( λ i → mul-nat-scalar-Semiring R (binomial-coefficient-Fin 1 i) (f i)) ∙ ( ap-binary ( add-Semiring R) ( left-unit-law-mul-nat-scalar-Semiring R (f (zero-Fin 1))) ( left-unit-law-mul-nat-scalar-Semiring R (f (one-Fin 1))))
Binomial sums are homotopy invariant
module _ {l : Level} (R : Semiring l) where htpy-binomial-sum-Semiring : (n : ℕ) {f g : functional-vec-Semiring R (succ-ℕ n)} → (f ~ g) → binomial-sum-Semiring R n f ＝ binomial-sum-Semiring R n g htpy-binomial-sum-Semiring n H = htpy-sum-Semiring R ( succ-ℕ n) ( λ i → ap ( mul-nat-scalar-Semiring R (binomial-coefficient-Fin n i)) ( H i))
Multiplication distributes over sums
module _ {l : Level} (R : Semiring l) where left-distributive-mul-binomial-sum-Semiring : (n : ℕ) (x : type-Semiring R) (f : functional-vec-Semiring R (succ-ℕ n)) → mul-Semiring R x (binomial-sum-Semiring R n f) ＝ binomial-sum-Semiring R n (λ i → mul-Semiring R x (f i)) left-distributive-mul-binomial-sum-Semiring n x f = ( left-distributive-mul-sum-Semiring R ( succ-ℕ n) ( x) ( λ i → mul-nat-scalar-Semiring R (binomial-coefficient-Fin n i) (f i))) ∙ ( htpy-sum-Semiring R ( succ-ℕ n) ( λ i → right-nat-scalar-law-mul-Semiring R ( binomial-coefficient-Fin n i) ( x) ( f i))) right-distributive-mul-binomial-sum-Semiring : (n : ℕ) (f : functional-vec-Semiring R (succ-ℕ n)) → (x : type-Semiring R) → mul-Semiring R (binomial-sum-Semiring R n f) x ＝ binomial-sum-Semiring R n (λ i → mul-Semiring R (f i) x) right-distributive-mul-binomial-sum-Semiring n f x = ( right-distributive-mul-sum-Semiring R ( succ-ℕ n) ( λ i → mul-nat-scalar-Semiring R (binomial-coefficient-Fin n i) (f i)) ( x)) ∙ ( htpy-sum-Semiring R ( succ-ℕ n) ( λ i → left-nat-scalar-law-mul-Semiring R ( binomial-coefficient-Fin n i) ( f i) ( x)))
Lemmas
Computing a left summand that will appear in the proof of the binomial theorem
module _ {l : Level} (R : Semiring l) where left-summand-binomial-theorem-Semiring : (n : ℕ) (x y : type-Semiring R) → (H : mul-Semiring R x y ＝ mul-Semiring R y x) → ( mul-Semiring R ( binomial-sum-Semiring R ( succ-ℕ n) ( λ i → mul-Semiring R ( power-Semiring R (nat-Fin (succ-ℕ (succ-ℕ n)) i) x) ( power-Semiring R ( dist-ℕ (nat-Fin (succ-ℕ (succ-ℕ n)) i) (succ-ℕ n)) y))) ( x)) ＝ ( add-Semiring R ( power-Semiring R (succ-ℕ (succ-ℕ n)) x) ( sum-Semiring R ( succ-ℕ n) ( λ i → mul-nat-scalar-Semiring R ( binomial-coefficient-Fin (succ-ℕ n) (inl-Fin (succ-ℕ n) i)) ( mul-Semiring R ( power-Semiring R ( succ-ℕ (nat-Fin (succ-ℕ n) i)) ( x)) ( power-Semiring R ( dist-ℕ (nat-Fin (succ-ℕ n) i) (succ-ℕ n)) ( y)))))) left-summand-binomial-theorem-Semiring n x y H = ( right-distributive-mul-binomial-sum-Semiring R ( succ-ℕ n) ( λ i → mul-Semiring R ( power-Semiring R ( nat-Fin (succ-ℕ (succ-ℕ n)) i) ( x)) ( power-Semiring R ( dist-ℕ (nat-Fin (succ-ℕ (succ-ℕ n)) i) (succ-ℕ n)) ( y))) ( x)) ∙ ( ( htpy-binomial-sum-Semiring R ( succ-ℕ n) ( λ i → ( ( associative-mul-Semiring R ( power-Semiring R (nat-Fin (succ-ℕ (succ-ℕ n)) i) x) ( power-Semiring R ( dist-ℕ (nat-Fin (succ-ℕ (succ-ℕ n)) i) (succ-ℕ n)) ( y)) ( x)) ∙ ( ( ap ( mul-Semiring R ( power-Semiring R (nat-Fin (succ-ℕ (succ-ℕ n)) i) x)) ( commute-powers-Semiring' R ( dist-ℕ (nat-Fin (succ-ℕ (succ-ℕ n)) i) (succ-ℕ n)) ( inv H))) ∙ ( inv ( associative-mul-Semiring R ( power-Semiring R (nat-Fin (succ-ℕ (succ-ℕ n)) i) x) ( x) ( power-Semiring R ( dist-ℕ (nat-Fin (succ-ℕ (succ-ℕ n)) i) (succ-ℕ n)) ( y)))))) ∙ ( ap ( mul-Semiring' R ( power-Semiring R ( dist-ℕ (nat-Fin (succ-ℕ (succ-ℕ n)) i) (succ-ℕ n)) ( y))) ( inv ( power-succ-Semiring R ( nat-Fin (succ-ℕ (succ-ℕ n)) i) ( x)))))) ∙ ( ( ap ( add-Semiring R _) ( ( ap-mul-nat-scalar-Semiring R ( is-one-on-diagonal-binomial-coefficient-ℕ (succ-ℕ n)) ( ap ( λ t → mul-Semiring R ( power-Semiring R (succ-ℕ (succ-ℕ n)) x) ( power-Semiring R t y)) ( dist-eq-ℕ' (succ-ℕ n)))) ∙ ( ( left-unit-law-mul-nat-scalar-Semiring R ( mul-Semiring R ( power-Semiring R (succ-ℕ (succ-ℕ n)) x) ( one-Semiring R))) ∙ ( right-unit-law-mul-Semiring R ( power-Semiring R (succ-ℕ (succ-ℕ n)) x))))) ∙ ( commutative-add-Semiring R ( sum-Semiring R ( succ-ℕ n) ( λ i → mul-nat-scalar-Semiring R ( binomial-coefficient-Fin (succ-ℕ n) (inl-Fin (succ-ℕ n) i)) ( mul-Semiring R ( power-Semiring R ( succ-ℕ (nat-Fin (succ-ℕ n) i)) ( x)) ( power-Semiring R ( dist-ℕ (nat-Fin (succ-ℕ n) i) (succ-ℕ n)) ( y))))) ( power-Semiring R (succ-ℕ (succ-ℕ n)) x))))
Computing a right summand that will appear in the proof of the binomial theorem
right-summand-binomial-theorem-Semiring : (n : ℕ) (x y : type-Semiring R) → ( mul-Semiring R ( binomial-sum-Semiring R ( succ-ℕ n) ( λ i → mul-Semiring R ( power-Semiring R ( nat-Fin (succ-ℕ (succ-ℕ n)) i) ( x)) ( power-Semiring R ( dist-ℕ (nat-Fin (succ-ℕ (succ-ℕ n)) i) (succ-ℕ n)) ( y)))) ( y)) ＝ ( add-Semiring R ( power-Semiring R (succ-ℕ (succ-ℕ n)) y) ( sum-Semiring R ( succ-ℕ n) ( λ i → mul-nat-scalar-Semiring R ( binomial-coefficient-ℕ ( succ-ℕ n) ( succ-ℕ (nat-Fin (succ-ℕ (succ-ℕ n)) (inl-Fin (succ-ℕ n) i)))) ( mul-Semiring R ( power-Semiring R ( succ-ℕ (nat-Fin (succ-ℕ n) i)) ( x)) ( power-Semiring R ( dist-ℕ (nat-Fin (succ-ℕ n) i) (succ-ℕ n)) ( y)))))) right-summand-binomial-theorem-Semiring n x y = ( right-distributive-mul-binomial-sum-Semiring R ( succ-ℕ n) ( λ i → mul-Semiring R ( power-Semiring R ( nat-Fin (succ-ℕ (succ-ℕ n)) i) ( x)) ( power-Semiring R ( dist-ℕ (nat-Fin (succ-ℕ (succ-ℕ n)) i) (succ-ℕ n)) ( y))) ( y)) ∙ ( ( htpy-binomial-sum-Semiring R ( succ-ℕ n) ( λ i → ( associative-mul-Semiring R ( power-Semiring R ( nat-Fin (succ-ℕ (succ-ℕ n)) i) ( x)) ( power-Semiring R ( dist-ℕ (nat-Fin (succ-ℕ (succ-ℕ n)) i) (succ-ℕ n)) ( y)) ( y)) ∙ ( ap ( mul-Semiring R ( power-Semiring R ( nat-Fin (succ-ℕ (succ-ℕ n)) i) ( x))) ( inv ( ap ( λ m → power-Semiring R m y) ( right-successor-law-dist-ℕ ( nat-Fin (succ-ℕ (succ-ℕ n)) i) ( succ-ℕ n) ( upper-bound-nat-Fin (succ-ℕ n) i)) ∙ ( power-succ-Semiring R ( dist-ℕ (nat-Fin (succ-ℕ (succ-ℕ n)) i) (succ-ℕ n)) ( y))))))) ∙ ( ( snoc-sum-Semiring R ( succ-ℕ n) ( λ i → mul-nat-scalar-Semiring R ( binomial-coefficient-Fin (succ-ℕ n) i) ( mul-Semiring R ( power-Semiring R ( nat-Fin (succ-ℕ (succ-ℕ n)) i) ( x)) ( power-Semiring R ( dist-ℕ (nat-Fin (succ-ℕ (succ-ℕ n)) i) (succ-ℕ (succ-ℕ n))) ( y)))) ( ( ap ( λ m → mul-nat-scalar-Semiring R ( binomial-coefficient-ℕ (succ-ℕ n) m) ( mul-Semiring R ( power-Semiring R m x) ( power-Semiring R ( dist-ℕ m (succ-ℕ (succ-ℕ n))) ( y)))) ( is-zero-nat-zero-Fin {n})) ∙ ( ( left-unit-law-mul-nat-scalar-Semiring R ( mul-Semiring R ( one-Semiring R) ( power-Semiring R (succ-ℕ (succ-ℕ n)) y))) ∙ ( left-unit-law-mul-Semiring R ( power-Semiring R (succ-ℕ (succ-ℕ n)) y))))) ∙ ( ap-add-Semiring R ( refl) ( htpy-sum-Semiring R ( succ-ℕ n) ( λ i → ( ap ( λ m → mul-nat-scalar-Semiring R ( binomial-coefficient-ℕ (succ-ℕ n) m) ( mul-Semiring R ( power-Semiring R m x) ( power-Semiring R ( dist-ℕ m (succ-ℕ (succ-ℕ n))) ( y)))) ( nat-inr-Fin (succ-ℕ n) i)))))))
Theorem
Binomial theorem for semirings
binomial-theorem-Semiring : {l : Level} (R : Semiring l) (n : ℕ) (x y : type-Semiring R) → mul-Semiring R x y ＝ mul-Semiring R y x → power-Semiring R n (add-Semiring R x y) ＝ binomial-sum-Semiring R n ( λ i → mul-Semiring R ( power-Semiring R (nat-Fin (succ-ℕ n) i) x) ( power-Semiring R (dist-ℕ (nat-Fin (succ-ℕ n) i) n) y)) binomial-theorem-Semiring R zero-ℕ x y H = inv ( ( sum-one-element-Semiring R ( λ i → mul-nat-scalar-Semiring R ( binomial-coefficient-Fin 0 i) ( mul-Semiring R ( power-Semiring R (nat-Fin 1 i) x) ( power-Semiring R (dist-ℕ (nat-Fin 1 i) 0) y)))) ∙ ( ( left-unit-law-mul-nat-scalar-Semiring R ( mul-Semiring R ( one-Semiring R) ( one-Semiring R))) ∙ ( left-unit-law-mul-Semiring R (one-Semiring R)))) binomial-theorem-Semiring R (succ-ℕ zero-ℕ) x y H = ( commutative-add-Semiring R x y) ∙ ( ( ap-binary ( add-Semiring R) ( ( inv (left-unit-law-mul-Semiring R y)) ∙ ( inv ( left-unit-law-mul-nat-scalar-Semiring R ( mul-Semiring R (one-Semiring R) y)))) ( ( inv (right-unit-law-mul-Semiring R x)) ∙ ( inv ( left-unit-law-mul-nat-scalar-Semiring R ( mul-Semiring R x (one-Semiring R)))))) ∙ ( inv ( sum-two-elements-Semiring R ( λ i → mul-nat-scalar-Semiring R ( binomial-coefficient-Fin 1 i) ( mul-Semiring R ( power-Semiring R (nat-Fin 2 i) x) ( power-Semiring R (dist-ℕ (nat-Fin 2 i) 1) y)))))) binomial-theorem-Semiring R (succ-ℕ (succ-ℕ n)) x y H = ( ap ( λ r → mul-Semiring R r (add-Semiring R x y)) ( binomial-theorem-Semiring R (succ-ℕ n) x y H)) ∙ ( ( left-distributive-mul-add-Semiring R _ x y) ∙ ( ( ap-add-Semiring R ( left-summand-binomial-theorem-Semiring R n x y H) ( right-summand-binomial-theorem-Semiring R n x y)) ∙ ( ( interchange-add-add-Semiring R ( power-Semiring R (succ-ℕ (succ-ℕ n)) x) ( sum-Semiring R ( succ-ℕ n) ( λ i → mul-nat-scalar-Semiring R ( binomial-coefficient-Fin (succ-ℕ n) (inl-Fin (succ-ℕ n) i)) ( mul-Semiring R ( power-Semiring R ( succ-ℕ (nat-Fin (succ-ℕ n) i)) ( x)) ( power-Semiring R ( dist-ℕ (nat-Fin (succ-ℕ n) i) (succ-ℕ n)) ( y))))) ( power-Semiring R (succ-ℕ (succ-ℕ n)) y) ( sum-Semiring R ( succ-ℕ n) ( λ i → mul-nat-scalar-Semiring R ( binomial-coefficient-ℕ ( succ-ℕ n) ( succ-ℕ (nat-Fin (succ-ℕ (succ-ℕ n)) (inl-Fin (succ-ℕ n) i)))) ( mul-Semiring R ( power-Semiring R ( succ-ℕ (nat-Fin (succ-ℕ n) i)) ( x)) ( power-Semiring R ( dist-ℕ (nat-Fin (succ-ℕ n) i) (succ-ℕ n)) ( y)))))) ∙ ( ( ap-add-Semiring R ( commutative-add-Semiring R ( power-Semiring R (succ-ℕ (succ-ℕ n)) x) ( power-Semiring R (succ-ℕ (succ-ℕ n)) y)) ( ( interchange-add-sum-Semiring R ( succ-ℕ n) ( λ i → mul-nat-scalar-Semiring R ( binomial-coefficient-Fin (succ-ℕ n) (inl-Fin (succ-ℕ n) i)) ( mul-Semiring R ( power-Semiring R ( succ-ℕ (nat-Fin (succ-ℕ n) i)) ( x)) ( power-Semiring R ( dist-ℕ (nat-Fin (succ-ℕ n) i) (succ-ℕ n)) ( y)))) ( λ i → mul-nat-scalar-Semiring R ( binomial-coefficient-ℕ ( succ-ℕ n) ( succ-ℕ ( nat-Fin (succ-ℕ (succ-ℕ n)) (inl-Fin (succ-ℕ n) i)))) ( mul-Semiring R ( power-Semiring R ( succ-ℕ (nat-Fin (succ-ℕ n) i)) ( x)) ( power-Semiring R ( dist-ℕ (nat-Fin (succ-ℕ n) i) (succ-ℕ n)) ( y))))) ∙ ( htpy-sum-Semiring R ( succ-ℕ n) ( λ i → ( inv ( right-distributive-mul-nat-scalar-add-Semiring R ( binomial-coefficient-ℕ ( succ-ℕ n) ( nat-Fin (succ-ℕ n) i)) ( binomial-coefficient-ℕ ( succ-ℕ n) ( succ-ℕ (nat-Fin (succ-ℕ n) i))) ( mul-Semiring R ( power-Semiring R ( succ-ℕ (nat-Fin (succ-ℕ n) i)) ( x)) ( power-Semiring R ( dist-ℕ (nat-Fin (succ-ℕ n) i) (succ-ℕ n)) ( y))))) ∙ ( ap ( λ m → mul-nat-scalar-Semiring R ( binomial-coefficient-ℕ (succ-ℕ (succ-ℕ n)) m) ( mul-Semiring R ( power-Semiring R m x) ( power-Semiring R ( dist-ℕ m (succ-ℕ (succ-ℕ n))) ( y)))) ( inv (nat-inr-Fin (succ-ℕ n) i))))))) ∙ ( ( right-swap-add-Semiring R ( power-Semiring R (succ-ℕ (succ-ℕ n)) y) ( power-Semiring R (succ-ℕ (succ-ℕ n)) x) ( _)) ∙ ( ( ap ( add-Semiring' R ( power-Semiring R (succ-ℕ (succ-ℕ n)) x)) ( inv ( snoc-sum-Semiring R ( succ-ℕ n) ( λ i → mul-nat-scalar-Semiring R ( binomial-coefficient-ℕ ( succ-ℕ (succ-ℕ n)) ( nat-Fin (succ-ℕ (succ-ℕ n)) i)) ( mul-Semiring R ( power-Semiring R ( nat-Fin (succ-ℕ (succ-ℕ n)) i) ( x)) ( power-Semiring R ( dist-ℕ ( nat-Fin (succ-ℕ (succ-ℕ n)) i) ( succ-ℕ (succ-ℕ n))) ( y)))) ( ( ap ( λ m → mul-nat-scalar-Semiring R ( binomial-coefficient-ℕ (succ-ℕ (succ-ℕ n)) m) ( mul-Semiring R ( power-Semiring R m x) ( power-Semiring R ( dist-ℕ m (succ-ℕ (succ-ℕ n))) ( y)))) ( is-zero-nat-zero-Fin {n})) ∙ ( ( left-unit-law-mul-nat-scalar-Semiring R ( mul-Semiring R ( one-Semiring R) ( power-Semiring R ( succ-ℕ (succ-ℕ n)) ( y)))) ∙ ( left-unit-law-mul-Semiring R ( power-Semiring R ( succ-ℕ (succ-ℕ n)) ( y)))))))) ∙ ( inv ( cons-sum-Semiring R ( succ-ℕ (succ-ℕ n)) ( λ i → mul-nat-scalar-Semiring R ( binomial-coefficient-Fin (succ-ℕ (succ-ℕ n)) i) ( mul-Semiring R ( power-Semiring R ( nat-Fin (succ-ℕ (succ-ℕ (succ-ℕ n))) i) ( x)) ( power-Semiring R ( dist-ℕ ( nat-Fin (succ-ℕ (succ-ℕ (succ-ℕ n))) i) ( succ-ℕ (succ-ℕ n))) ( y)))) ( ( ap-mul-nat-scalar-Semiring R ( is-one-on-diagonal-binomial-coefficient-ℕ ( succ-ℕ (succ-ℕ n))) ( ( ap ( mul-Semiring R ( power-Semiring R (succ-ℕ (succ-ℕ n)) x)) ( ap ( λ m → power-Semiring R m y) ( dist-eq-ℕ' (succ-ℕ (succ-ℕ n))))) ∙ ( right-unit-law-mul-Semiring R ( power-Semiring R (succ-ℕ (succ-ℕ n)) x)))) ∙ ( left-unit-law-mul-nat-scalar-Semiring R ( power-Semiring R ( succ-ℕ (succ-ℕ n)) ( x))))))))))))
Corollaries
If x commutes with y, then we can compute (x+y)ⁿ⁺ᵐ as a linear combination of xⁿ and yᵐ
is-linear-combination-power-add-Semiring : {l : Level} (R : Semiring l) (n m : ℕ) (x y : type-Semiring R) → mul-Semiring R x y ＝ mul-Semiring R y x → power-Semiring R (n +ℕ m) (add-Semiring R x y) ＝ add-Semiring R ( mul-Semiring R ( power-Semiring R m y) ( sum-Semiring R n ( λ i → mul-nat-scalar-Semiring R ( binomial-coefficient-ℕ (n +ℕ m) (nat-Fin n i)) ( mul-Semiring R ( power-Semiring R (nat-Fin n i) x) ( power-Semiring R (dist-ℕ (nat-Fin n i) n) y))))) ( mul-Semiring R ( power-Semiring R n x) ( sum-Semiring R ( succ-ℕ m) ( λ i → mul-nat-scalar-Semiring R ( binomial-coefficient-ℕ ( n +ℕ m) ( n +ℕ (nat-Fin (succ-ℕ m) i))) ( mul-Semiring R ( power-Semiring R (nat-Fin (succ-ℕ m) i) x) ( power-Semiring R (dist-ℕ (nat-Fin (succ-ℕ m) i) m) y))))) is-linear-combination-power-add-Semiring R n m x y H = ( binomial-theorem-Semiring R (n +ℕ m) x y H) ∙ ( ( split-sum-Semiring R n ( succ-ℕ m) ( λ i → mul-nat-scalar-Semiring R ( binomial-coefficient-ℕ ( n +ℕ m) ( nat-Fin (n +ℕ (succ-ℕ m)) i)) ( mul-Semiring R ( power-Semiring R ( nat-Fin (n +ℕ (succ-ℕ m)) i) ( x)) ( power-Semiring R ( dist-ℕ ( nat-Fin (n +ℕ (succ-ℕ m)) i) ( n +ℕ m)) ( y))))) ∙ ( ( ap-add-Semiring R ( ( htpy-sum-Semiring R n ( λ i → ( ap ( λ u → mul-nat-scalar-Semiring R ( binomial-coefficient-ℕ (n +ℕ m) u) ( mul-Semiring R ( power-Semiring R u x) ( power-Semiring R ( dist-ℕ u (n +ℕ m)) ( y)))) ( nat-inl-coproduct-Fin n m i)) ∙ ( ( ( ap ( mul-nat-scalar-Semiring R ( binomial-coefficient-ℕ ( n +ℕ m) ( nat-Fin n i))) ( ( ap ( mul-Semiring R ( power-Semiring R ( nat-Fin n i) ( x))) ( ( ap ( λ u → power-Semiring R u y) ( ( inv ( triangle-equality-dist-ℕ ( nat-Fin n i) ( n) ( n +ℕ m) ( upper-bound-nat-Fin' n i) ( leq-add-ℕ n m)) ∙ ( ap ( (dist-ℕ (nat-Fin n i) n) +ℕ_) ( dist-add-ℕ n m))) ∙ ( commutative-add-ℕ ( dist-ℕ (nat-Fin n i) n) ( m)))) ∙ ( ( distributive-power-add-Semiring R m ( dist-ℕ (nat-Fin n i) n))))) ∙ ( ( inv ( associative-mul-Semiring R ( power-Semiring R (nat-Fin n i) x) ( power-Semiring R m y) ( power-Semiring R (dist-ℕ (nat-Fin n i) n) y))) ∙ ( ( ap ( mul-Semiring' R ( power-Semiring R (dist-ℕ (nat-Fin n i) n) y)) ( commute-powers-Semiring R (nat-Fin n i) m H)) ∙ ( associative-mul-Semiring R ( power-Semiring R m y) ( power-Semiring R (nat-Fin n i) x) ( power-Semiring R ( dist-ℕ (nat-Fin n i) n) ( y))))))) ∙ ( inv ( right-nat-scalar-law-mul-Semiring R ( binomial-coefficient-ℕ ( n +ℕ m) ( nat-Fin n i)) ( power-Semiring R m y) ( mul-Semiring R ( power-Semiring R (nat-Fin n i) x) ( power-Semiring R ( dist-ℕ (nat-Fin n i) n) ( y))))))))) ∙ ( ( inv ( left-distributive-mul-sum-Semiring R n ( power-Semiring R m y) ( λ i → mul-nat-scalar-Semiring R ( binomial-coefficient-ℕ (n +ℕ m) (nat-Fin n i)) ( mul-Semiring R ( power-Semiring R (nat-Fin n i) x) ( power-Semiring R (dist-ℕ (nat-Fin n i) n) y))))))) ( ( htpy-sum-Semiring R ( succ-ℕ m) ( λ i → ( ap ( λ u → mul-nat-scalar-Semiring R ( binomial-coefficient-ℕ (n +ℕ m) u) ( mul-Semiring R ( power-Semiring R u x) ( power-Semiring R ( dist-ℕ u (n +ℕ m)) ( y)))) ( nat-inr-coproduct-Fin n (succ-ℕ m) i)) ∙ ( ( ap ( mul-nat-scalar-Semiring R ( binomial-coefficient-ℕ ( n +ℕ m) ( n +ℕ (nat-Fin (succ-ℕ m) i)))) ( ap-mul-Semiring R ( distributive-power-add-Semiring R n ( nat-Fin (succ-ℕ m) i)) ( ap ( λ u → power-Semiring R u y) ( translation-invariant-dist-ℕ ( n) ( nat-Fin (succ-ℕ m) i) ( m))) ∙ ( associative-mul-Semiring R ( power-Semiring R n x) ( power-Semiring R (nat-Fin (succ-ℕ m) i) x) ( power-Semiring R ( dist-ℕ (nat-Fin (succ-ℕ m) i) m) ( y))))) ∙ ( inv ( right-nat-scalar-law-mul-Semiring R ( binomial-coefficient-ℕ ( n +ℕ m) ( n +ℕ (nat-Fin (succ-ℕ m) i))) ( power-Semiring R n x) ( mul-Semiring R ( power-Semiring R (nat-Fin (succ-ℕ m) i) x) ( power-Semiring R ( dist-ℕ (nat-Fin (succ-ℕ m) i) m) ( y)))))))) ∙ ( inv ( left-distributive-mul-sum-Semiring R ( succ-ℕ m) ( power-Semiring R n x) ( λ i → mul-nat-scalar-Semiring R ( binomial-coefficient-ℕ ( n +ℕ m) ( n +ℕ (nat-Fin (succ-ℕ m) i))) ( mul-Semiring R ( power-Semiring R (nat-Fin (succ-ℕ m) i) x) ( power-Semiring R ( dist-ℕ (nat-Fin (succ-ℕ m) i) m) ( y))))))))))
Recent changes
- 2024-02-06. Fredrik Bakke. Rename
(co)prodto(co)product(#1017). - 2023-08-21. Egbert Rijke and Fredrik Bakke. Cyclic groups (#697).
- 2023-06-10. Egbert Rijke and Fredrik Bakke. Cleaning up synthetic homotopy theory (#649).
- 2023-05-16. Fredrik Bakke. Swap from
mdtotextcode blocks (#622). - 2023-05-13. Fredrik Bakke. Refactor to use infix binary operators for arithmetic (#620).