clantr(3) on Linux
The text ca61f2cdf63c, as Debian 2.2 (Potato), Debian 2.1 (Slink), Debian 2.0 (Hamm) shipped it.
return the value of the one norm, or the Frobenius norm, or the infinity norm, or the element of largest absolute value of a trapezoidal or triangular matrix A