I was reading nominal unification paper. I could not understand the proof of a lemma. The paper is here nominal unification. The lemma is following. $\sigma$ is a substitution, $\pi$ is a permutation (swapping of atoms). Lemma 3.3. if $\Delta \vdash \sigma(\pi .X) \approx \sigma(t)$, then $\si...

I developed a randomized self-adjusting binary search tree years ago, which I called a shuffle tree, but was unable to ever have it published because my proofs were rejected (with little explanation). I've since given up the hope of publishing (I'm not an academic so it doesn't matter so much), ...

I believe that reading vintage codes or codes or papers where some idea was introduced for the first time will expose the concept in its simplest form and hence will lead to clearer and deeper understanding as it will be free of profuse interspersing of many libraries and framework and hence we c...