Dominosa is a logic puzzle with a similar feel to Sudoku, and I've recently added it to Donimoes, my collection of domino puzzles and games. Given a grid of numbers, you have to lay out the dominoes so they match the numbers, without duplicated or missing dominoes. See Monday's problem for complete rules and and an example solution.
Today's problem is a little bigger and a little more challenging. Good luck, and post your solution as an answer.
If you like this puzzle, watch for a more challenging problem on Friday.