The Tower of Hanoi problem consists of moving a tower of 64 disks, each smaller than the one below it, originally existing on one peg, to a second peg, using a third peg for intermediate moves.

The Tower of Hanoi consists of a small board on which three identical cylindrical rods are mounted. On the left rod there are five disks of different sizes with a hole in the middle.

To support this claim, the paper uses the Tower of Hanoi puzzle—a classic problem requiring the movement of disks between pegs under specific rules—as a key benchmark. The complexity of this puzzle ...

The problems researchers used to evaluate the reasoning models, which they call LRMs or Large Reasoning Models, are classic logic puzzles like the Tower of Hanoi.