Logic Masters Deutschland e.V.

So much for not posting on LMD anymore, but what can I say. it’s been really nice seeing all the activity on my catalog despite being almost completely absent for half a year now, including many Chinese fans, that I’ve noticed from the names – 你好！Quite the invitation to make more puzzles, and so, here’s one (and to be followed by a bonus one too). The tentative difficulty is largely based on the ruleset itself, more than on any given deduction.

For puzzle link-trail fans, it reuses in a more serious way ideas from my meme puzzle We Have Palindromes at Home, itself inspired by sanabas’ Schrodingerenban puzzle, and mixes in ideas from puzzles of bodemeister as well, who, incidentally, was also the tester for this one, so huge thanks to him!



RULES

CHAOS CONSTRUCTION
• Divide the grid into nine orthogonally connected regions of nine cells each.
• The leftmost cell in the top row of a region is its Region Indicator; the rightmost cell in the bottom row is its Region Closer.
• Every region must contain one S-cell and one Doubler, occupying its Indicator and Closer in either order.

S-CELLS
• Fill the grid with the digits 0-9 so that no digit repeats in any row, column, or region.
• Each row, column, and region contains exactly one S-cell. An S-cell contains *any* two digits whose value is their sum.

DOUBLERS
• Each row, column, and region also contains exactly one Doubler. Together, the Doublers contain the digits 1–9 exactly once each, and each Doubler's value is twice its digit.

ARROWS
• An arrow clue of value *N* indicates that, in the direction of each arrow, a Region Indicator or Region Closer lies exactly N cells away. A clue of 0 points to its own cell.

MODIFIED PALINDROMES
• Grey lines read the same forwards and backwards by value. E.g. (3+2)-8-0-4*-5.
• On the pyramid palindrome, every cell must serve as both the start and end of a five-cell palindrome looping back to itself.
• Digits may not repeat on a grey line, whether they appear normally, in an S-cell, or in a Doubler.