Normal sudoku rules apply.
Draw an orthogonally connected loop that does not branch, overlap or touch itself. Every cell on the loop indexes a different cell in the grid and they are the same digit (no loop cell indexes itself). If a loop cell is in RaCb then it indexes R(a+b)C(a*b). If the sum or product exceed 9, then add the digits repeatedly until a single digit remains.
Arrows are off the loop and count the number of loop cells in the indicated direction.
Adjacent digits on a green line differ by at least 5. A white dot between 2 cells means they are consecutive. An inequality sign points to the smaller digit.
Solution code: Column 4, put loop segments in ()
yesterday, 21:58 by 0123coolkid
Neat logic! Narrow solve path
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