Tak (function)
In computer science, the Tak function is a recursive function, named after Ikuo Takeuchi. It is defined as follows: τ ( x , y , z ) = { τ ( τ ( x − 1 , y , z ) , τ ( y − 1 , z , x ) , τ ( z − 1 , x , y ) ) if y < x z otherwise {\displaystyle \tau (x,y,z)={\begin{cases}\tau (\tau (x-1,y,z),\tau (y-1,z,x),\tau (z-1,x,y))&{\text{if }}y<x\\z&{\text{otherwise}}\end{cases}}} This function is often used as a benchmark for languages with optimization for recursion.