I've actually seen this usage pattern in the practical usage of logic programming libraries. Common Lisp's Screamer [1], for instance, or Clojure's less-mature

I've actually seen this usage pattern in the practical usage of logic programming libraries. Common Lisp's Screamer [1], for instance, or Clojure's less-mature core.logic [2]. Though to be fair, both of these libraries are in Lisp languages, which inherently support the design pattern of slipping into/out-of DSLs. [1] http://nikodemus.github.io/screamer/ http://nikodemus.github.io/screamer/ [2] https://github.com/clojure/core.logic https://github.com/clojure/core.logic