Fortron automatic recursion

This amazing feature let you create functions with automatic recursion in it. I try to explain: you define a function, then executing some code in it and, randomly, the function calls itself with the last defined variables as parameters.

Check out this little example:

@autorecursion(probability=45%)
Fortrfunc autoexample(arg0, arg1) {
i is 1
a is 7
o ithinkis 8
arg0 fortrsum oai
arg1 fortrmul aio
}

In this case, with a probability of 45% this function calls itself with two among i, a, o, arg0, arg1 as parameters, but you don't know which of these, because the time of recall is also random.