The author had (too much) fun using a combination of the SKI combinator calculus [1] and the &quot;B, C, K, W&quot; system [2].<p>[1] <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;SKI_combinator_calculus" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;SKI_combinator_calculus</a>
[2] <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;B,_C,_K,_W_system" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;B,_C,_K,_W_system</a>