Source code in the picat programming language

main => 
    hanoi(3, left, center, right).

hanoi(0, _From, _To, _Via) => true.
hanoi(N, From, To, Via) =>
    hanoi(N - 1, From, Via, To),
    printf("Move disk %w from pole %w to pole %w\n", N, From, To),
    hanoi(N - 1, Via, To, From).

main => 
   hanoi(64).

hanoi(N) => 
   printf("N=%d\n", N),
   Count = move(N, left, center, right) ,
   printf("count=%w, theoretical=%w\n", Count, 2**N-1).
 
table
move(0, _From, _To, _Via) = 0.
move(N, From, To, Via) = Count => 
    Count1 = move(N - 1, From, Via, To),
    Count2 = move(N - 1, Via, To, From),
    Count = Count1+Count2+1.