Right, the interesting case would be the formal proof. Though, I suspect there are fewer high-level languages where memory bugs are actually impossible than you

Right, the interesting case would be the formal proof. Though, I suspect there are fewer high-level languages where memory bugs are actually impossible than you would naively think. I've segfaulted Python by accident, only using the standard library (concurrency shenanigans if I recall). You can probably do worse if you try. To make a truly memory-safe language, you would need to carefully design and implement the standard library, disallow all native code extensions, and probably more I'm not smart enough to figure out. So, not Java, not Python. Maybe some Schemes?