Interlocking #4

This is Interlocking #4 (and probably the last of the series).

This is a 4x4x4 puzzles with 4 pieces. According to burrtools, the level is 9.4.7 (you need 9 moves to remove the first piece), and it is quite difficult...

As for the first 3 puzzle of this collection, this puzzle was computed with a genetic algorithm. A short description of this algorithm can be found on my personal webpage here: https://www.ceremade.dauphine.fr/~gontier/Puzzles/InterlockingPuzzles/interlocking.html

I designed the stl file with openscad, using the puzzlecad file of asiegel (here: https://www.thingiverse.com/thing:3198014). The pieces here are in a split version for easy printing. Please refer to the picture of the pieces for the assembly.