Column.sqrt

The unary mathematical transforms (ADR-2026-10-30-01): sqrt, cbrt, exp, log, log2, log10, log1p, expm1, sin, cos, tan, asin, acos and atan share one contract. FLOAT32 and FLOAT64 keep their kind (FLOAT32 computes in double, rounded once); integer kinds promote to FLOAT64; exceptional values follow IEEE and never throw (sqrt(-1) = NaN, log(0) = -inf, overflow to infinities); nulls propagate.