Here is a 'KRRBNN vs kqrbn' mate in 3 chess problem generated by the prototype computer program, Chesthetica, using the Digital Synaptic Neural Substrate AI computational creativity method. There is also no proven limit to the quantity or type of legal compositions that can be automatically generated. Noteworthy here is that a chess position with over 7 pieces could not have been derived or taken from an endgame tablebase because 7 pieces is the present limit.
Humans have been composing original chess problems for over a thousand years. Now a computer can do it too. Chesthetica composes everything autonomously (no human intervention) and even chooses the main line of the solution to show you. Leave a comment below, if you like. Solving chess puzzles like this can also help improve your game.