Yes, i almost understand. Thank you for your clear explanation.
I only need to apply it on a simple example
When i evaluate f[2, 3], the result is {f[2], f[3]}. Logically, the recursive function stops because each function has only one argument.
But I evaluate f[{2, 3}, {3, 3}], the result is {f[{2, 3}], f[{3, 3}]}. I would like to Mathematica continue the indentation. I believe that it becomes i didn't use the syntax of the list well.
May you help me to correct my syntax so that I can test this kind of recursive function on a example ?
Thanks a lot for your help.