Thank you, I had read the FAQ:<p><a href="http:&#x2F;&#x2F;docs.idris-lang.org&#x2F;en&#x2F;latest&#x2F;faq&#x2F;faq.html" rel="nofollow">http:&#x2F;&#x2F;docs.idris-lang.org&#x2F;en&#x2F;latest&#x2F;faq&#x2F;faq.html</a><p>but could not infer why a dragon from Ivor the engine had been chosen. That the author had previously written a proof engine makes all the sense now. :)