sptsvx(3) on Linux
The text 69e15e0f23d7, as Debian 4.0 (Etch), Debian 3.1 (Sarge) shipped it.
use the factorization A = L*D*L**T to compute the solution to a real system of linear equations A*X = B, where A is an N-by-N symmetric positive definite tridiagonal matrix and X and B are N-by-NRHS matrices