liblapack-doc 3.9.0-1build1 (arm64 binary) in ubuntu focal

 LAPACK version 3.X is a comprehensive FORTRAN library that does
 linear algebra operations including matrix inversions, least
 squared solutions to linear sets of equations, eigenvector
 analysis, singular value decomposition, etc. It is a very
 comprehensive and reputable package that has found extensive
 use in the scientific community.
 .
 This package contains:
  - manpages of BLAS and LAPACK routines,
  - the Lapack User's Guide manual (in HTML),
  - the manual for the LAPACKE C interface to LAPACK (in PDF).