Reference · Non-negative rationals
rainbow.math.rational.nnrat.additive-reassociation
Associativity and reusable summand reorder laws for native nonnegative rationals. The foundational associativity proof unfolds rational addition to its numerator/positive-denominator cross product and asks the verified nat semiring normalizer for a kernel-checkable equality proof. The two downstream laws are then assembled from associativity, commutativity, congruence, symmetry, and transitivity at the nnrat equivalence layer.
nnrat/add-associative
nnrat/add-associative : (a b c : ℚ≥0) → a + b + c = a + (b + c)
+ = nnrat/add= = nnrat/equivalent: equality of rational valuesℚ≥0 = nnrat/NonnegativeRational
nnrat/add-swap-right
nnrat/add-swap-right : (a b c : ℚ≥0) → a + (b + c) = b + (a + c)
+ = nnrat/add= = nnrat/equivalent: equality of rational valuesℚ≥0 = nnrat/NonnegativeRational
nnrat/add-four-reorder
nnrat/add-four-reorder : (a b c d : ℚ≥0) → a + b + (c + d) = a + c + (b + d)
+ = nnrat/add= = nnrat/equivalent: equality of rational valuesℚ≥0 = nnrat/NonnegativeRational