Ok, but MiniKanren isn't intrinsic to Scheme. I agree Racket makes it especially easy to embed sub languages, but you could embed core relational Prolog just as well as MiniKanren. My understanding of your statement is that Scheme and MiniKanren share sexp syntax, but the same applies: you could embed an sexp-based Prolog just as well. The only remaining MiniKanren advantage is then to have a complete search strategy, this I concede.