Which ones? The ones that are returning an invalid result or the ones where an Amb operator is not really needed and just don’t use it (or just cheat defining it as the id function)?
Take, for example, Tcl brutforce, Clojure and Wolfram which is written to only solve an example with words.
Implementation in D does not seem to be right: they just define a function that takes list of lists and a function, which is not exactly what is required in problem statement.