dlasr(3) on Linux
The text 781e20b1ff85, as Debian 2.2 (Potato), Debian 2.1 (Slink), Debian 2.0 (Hamm) shipped it.
perform the transformation A := P*A, when SIDE = 'L' or 'l' ( Left-hand side ) A := A*P', when SIDE = 'R' or 'r' ( Right-hand side ) where A is an m by n real matrix and P is an orthogonal matrix,