Reference · Finite sums
rainbow.math.sums.value-append
Split the existing expr-sum-value at any Nat offset a: sum F (b+a) ~ sum F a + sum (fn i. F(i+a)) b. All Nat lengths, including zero; no sign or boundedness assumptions. Equality is the existing signed-rational equivalence, not raw-pair Eq.
signed/expr-sum-value-append
signed/expr-sum-value-append : (F : ℕ → ℚ) (a b : ℕ) → signed/expr-sum-value F (algebra/nat-add b a) = signed/expr-sum-value F a + signed/expr-sum-value (fun i => F (algebra/nat-add i a)) b
+ = signed/add= = signed/equivalent: equality of rational valuesℕ = data/Natℚ = signed/SignedRational