Logic Masters Deutschland e.V.

Normal Sudoku Rules Apply.
Digits connected by a black dot form a 2:1 ratio. Not all dots are necessarily given.

Ring Ring rules apply.
Draw lines through the center of cells to fill each empty cell with a rectangular loop.
-Loops may cross each other, but may not overlap or share a corner.
-Loops cannot go through shaded (indexer) cells or cross through black dots.

Indexer Cells: Caged cells in the grid are indexer cells as follows:
-Red cells are Column Indexers (C cages). The digit in a red cell gives the placement of that cell's column number in its row. (i.e. if row 6, column 5 contained a 9, that would place a 5 in row 6, column 9.)
-Green cells are Row Indexers (R cages). The digit in a green cell gives the placement of that cell's row number in its column. (i.e. if row 2, column 6 contained a 4, that would place a 2 in row 4, column 6.)
-Blue cells are Box Indexers (B cages). The digit in a blue cell gives the location of that cell's box position in the box. (i.e. if row 3, column 6 [position 9 in the box] contained a 2, that would place a 9 in row 1, column 5 [position 2 in the box])

The value of a digit in a Red column indexer cell (C cage) counts the number of cells in that column that contain vertical components of a loop (corner or straight vertical)
The value of a digit in a Green row indexer cell (R cage) counts the number of cells in that row that contain horizontal components of a loop (corner or straight horizontal)
The value of a digit in a Blue box indexer cell is unrestricted.

Note: r1c9 is both Row and Column Indexer Links
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