Reference · Non-negative rationals
rainbow.math.rational.nnrat.distance-translation
Removing common nonnegative mass preserves exact rational distance. The proof uses the additive-radius characterization in both directions, additive monotonicity, and cancellation; no truncated subtraction is assumed.
nnrat/distance-add-right
nnrat/distance-add-right : (a b common : ℚ≥0) → nnrat/distance (a + common) (b + common) = nnrat/distance a b
+ = nnrat/add= = nnrat/equivalent: equality of rational valuesℚ≥0 = nnrat/NonnegativeRational