Computer-Generated Chess Problem 03991

Now, here we have a 'KRRB vs kbn' mate in four chess construct composed autonomously by a computer program, Chesthetica, using the Digital Synaptic Neural Substrate (DSNS) computational creativity approach. It doesn't use endgame tablebases, neural networks or any kind of machine learning found in traditional AI.

4b3/6Bk/6R1/6K1/6R1/8/6n1/8 w - - 0 1
White to Play and Mate in 4
Chesthetica v12.64 (Selangor, Malaysia)
Generated on 16 Jan 2023 at 6:54:26 AMSolvability Estimate = Difficult
Some of the earliest chess problems by humans are over 10 centuries old but original ones by computer are very recent. What was the machine 'thinking' when it came up with this? Do share and try out some of the others too. Take some time to study the analysis and you might appreciate the puzzle a little more.
A Similar Chess Problem by Chesthetica: 03798
Solution