Here is my solution for the [[problem

Crossing the river]] I posted earlier.

Pol: Policeman; Pris: Prisoner; b: boy; g: girl.

Pol + Pris Pol Pol + b Pol + Pris father + b father father + mother mother Pol + Pris father father + mother mother mother + g Pol + Pris Pol + g Pol Pol + Pris

Now, is this the shortest solution?