libkernlib1-gfortran binary package in Ubuntu Focal armhf

 CERNLIB is a suite of data analysis tools and libraries created for
 use in physics experiments, but also with applications to other
 fields such as the biological sciences.
 .
 The kernlib library contains a rather miscellaneous set of basic numerical,
 bitwise, and system-dependent functions used by other CERN libraries and
 programs.
 .
 Note that in order to compile and link programs against this library, you
 must also install the libkernlib1-dev package.

Source package