slasd4(3) on Linux
The text cb4fc34efcba, as Debian 4.0 (Etch), Debian 3.1 (Sarge) shipped it.
subroutine computes the square root of the I-th updated eigenvalue of a positive symmetric rank-one modification to a positive diagonal matrix whose entries are given as the squares of the corresponding entries in the array d, and that 0 <= D(i) < D(j) for i < j and that RHO > 0