Now the ensemble of bookkeeping functions can be called by a top function move. This function has the same signature as is constrained and demanded by Thrun's instruction. The development of the functions demonstrates clearly that the pure functional style is more demanding in comparison to an imperative solution with side effects. It would have been more productive to create the program in R. Though R is mainly a function-based language - similar to Scheme and influenced by Scheme it provides many imperative looking features disguising the pure functional style.
"Write code that makes the robot move twice and then prints out the resulting distribution, starting with the initial distribution p = [0, 1, 0, 0, 0]" (Thrun, AI for Robotics)