Logic Masters Deutschland e.V.

I set this puzzle as Fjam's present for the CTC discord Secret Santa event. He kindly encouraged me to publish it for you all. I wanted it unusual, fun and challenging for him. I can at least say that it was all that for me, as it is a puzzle very different from anything I'd set before.

In particular, it is in a way the opposite twin from my last puzzle Lyly, which is also about double arrows and shares some similarities, but offers a completely different solving experience from minimalist ruleset and clues. Please consider having a look at Lyly too, it's a puzzle I'm very happy with.

Have fun solving! I'll be happy to read your comments.

Rules :

Normal sudoku rules apply. Nine cells - one in each row, column and box - containing digits 1-9 once each are doublers.

Draw a non-intersecting orthogonal path through the center of some cells, including every doubler and excluding the shaded cells. The path may be open ended or a closed loop, it's up to the solver to find out.

Normal double arrow rules apply along the path, with doubler cells acting as circles : the sum of the digits between two doublers is equal to the sum of these doublers.
If the path is open ended and does not end with a doubler, the end must form a standard arrow with the last doubler acting as the circle : the digits in the end section of the path sum to that doubler.
Digits in doublers count as double their value for the purpose of arrows and double arrows.

Small number clues give the sum of the digits on the path in the (up to 9) neighbouring cells (including itself). In such a sum, digits may repeat and doublers count as double their value.

Digits in squares indicate the number of cells on the path in the (up to 9) neighbouring cells (including itself).
(Note that doublers do not apply to squares.)

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Example : this illustrates several cases you could encounter in the puzzle. Red digits would have been determined to be doublers. Here, we have for instance :
2x4=7+1 (standard arrow)
2x(3+5)=6+8+2 (double arrow)
18=1+7+2+3+3+2 (small number clue)