Place the nine half dominoes into the grid, without rotating or reflecting them. Numbers indicate how many dots are there in the given row, column or diagonal.
(Rules and example from WPC 2011 IB)
Nine half dominoes are one of the following patterns of pips. (Taken from Ulrich Voigt's Half Dominoes puzzle
History of the puzzle
Appeared on WPC 1999/Part 5, an "innovative" round. The author of the puzzle is unknown.