Core uses nil instead of empty for some array lemmas and I keep getting caught by that, so I'm proposing to add aliases for the empty variants. I'm also proposing to add mem_singleton since that one comes up often enough that I'd like to avoid going through list every time.
Core uses
nil
instead ofempty
for some array lemmas and I keep getting caught by that, so I'm proposing to add aliases for theempty
variants. I'm also proposing to addmem_singleton
since that one comes up often enough that I'd like to avoid going through list every time.