My new RPi4 arrived yesterday, and I'm trying out the 64bit OS. Most of it has been fine. As a large program to try out the 64 bit space Common LISP in its SBCL implementation installed and ran fine with the McClim GUI package as a trial. However, Wolfram Mathematica will not install (and I've posted it to the GitHub site) so in case anyone can shed light on what the problem is I'd be grateful.
I have installed Java openjdk version "11.0.7" 2020-04-14 and Fortran but that installed libgfortran5:armhf
Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation: The following packages have unmet dependencies: wolfram-engine:armhf : Depends: oracle-java7-jdk:armhf but it is not installable or oracle-java8-jdk:armhf but it is not installable or openjdk-11-jdk:armhf but it is not going to be installed Depends: libssl1.0.2:armhf but it is not installable Depends: liboauth0:armhf but it is not going to be installed Depends: libgfortran3:armhf but it is not installable