petsc3.12-doc 3.12.3+dfsg1-1 (s390x binary) in ubuntu focal

 PETSc is the "Portable Extensible Toolkit for Scientific
 Computation", a suite of data structures and routines for the
 scalable (parallel) solution of scientific applications modeled by
 partial differential equations. It employs the MPI standard for all
 message-passing communication. Several sample scientific
 applications, as well as various papers and talks, demonstrate the
 features of the PETSc libraries.
 .
 This package contains documentation for developing with PETSc 3.12.