Fix powershell and elisp predicate/equality issues revealed by #665

[kanaka]

PR #665 added some new predicate and equality tests that revealed some issues in elisp and powershell. Here is the failing CI run: https://github.com/kanaka/mal/actions/runs/10537666665/job/29199344773?pr=665

[asarhaddon]

I am preparing a fix for both.