3.1.1

Indicator primitives refuse non-finite derived arithmetic with
DataValidationError. Cutler's RSI checks the combined movement before
division, so finite upward and downward totals whose sum overflows can no
longer produce a plausible zero. Relative range, log-volume ratio and
price-to-moving-average validate their derived readings, including quotient
overflow and underflow to zero before a log. Ordinary formulas, boundary
conventions, missing-input nulls, lookbacks and feature identities are
unchanged.