Note copysign procedure.

diff --git a/src/relnotes/arith b/src/relnotes/arith
index 20e36b040ed9b49862e6d30f595d7ebf62295c7a..b736ec10335824a68cd032c15f1e98f404240339 100644 (file)
--- a/src/relnotes/arith
+++ b/src/relnotes/arith
@@ -16,3 +16,5 @@ New procedures:
 . (logistic-1/2 x) = (- (logistic x) 1/2), inverse of logit1/2+
 . (logsumexp (list x y z ...)) = log (e^x + e^y + e^z + ...),
   guaranteed not to overflow or underflow
+. (copysign m s) returns a real number with the magnitude of m and
+  the sign of s.