> any remaining unsoundness bugs are most likely in Lean's compiler or runtime (including the bignum library). It is very unlikely that the same bug also exists in the Rust compiler or runtime, so by checking a proof with both con-leche and con-ron, you gain a high level of protection against this class of bugs

An awful lot of references for arbitrary precision arithmetic are just repackaging Knuth’s explanations, so I wonder if there could in fact be a bug in common (Although you would like to assume every other piece of software using them would have also hit any issues by now, so maybe it is fine)