Install OCaml following the instructions on the Cornell CS 3110 2019 Fall course website.
make play
Type select [difficulty] to begin. There are [easy], [medium], [hard] difficulties. You will be shown a deck on the upper left corner. Your hand is in the top left corner. The first two symbols are the rank and suite. The third is the position in your hand. Use play [n] where n is the card position you want to play.