Let us do Towers in c

push(&left,pop(&center));   // Take a ring from the center post and put it on the left post

The & is a signal we use in  c, it is the address pointer to the rings.

size(*top(&center))   // Tell me the ring size at the top of the center post
// we would do this to obey the Tower of Hanoi syntax, no big rings on top of small rings.
// The * is a special character we use, it means, the thing at that address, the inversion of the &

Play the game, once you play the game a few days, go get a job at Google writing c code.