[crustycoder]

Or perhaps just use a language that's designed to solve those sorts of problems? In 14 lines of code.

https://www.swi-prolog.org/pldoc/man?section=clpfd-sudoku

[cenamus]

Is there a similarly short/simple solution not using all of the built ins? Haven't worked with prolog in a while but should be easy enough with primitives (albeit with more duplication)?

[crustycoder]

Well no, not really. The whole point is to use the appropriate tool for the task at hand. In this case it's the CLP(FD) library, https://www.swi-prolog.org/pldoc/man?section=clpfd

[nurettin]

Why not just

    blocks(Rows, Blocks), maplist(all_distinct, Blocks), maplist(label, Rows)