djinn 2014.9.7-9build2 (amd64 binary) in ubuntu focal

 Djinn uses a theorem prover for intuitionistic propositional logic to
 generate a Haskell expression when given a type.
 .
 Given a type the program will deduce an expression of this type, if one
 exists. If the Djinn says the type is not realizable it is because there
 is no (total) expression of the given type.