Rules: A wall is hidden in the grid. Each horizontal row contains bricks of 1 unit height and length 1 and longer, lodged one beside the other. Two bricks of the same length cannot share an edge. Each brick has either a single digit, or an arithmetic expression with two single-digit numbers from 1 to 9, written on it, one number per cell. One of four standard operators +, -, x, and /, is used in each operation. The length of the brick must be equal to the expression's result or the lone digit it contains. Expresions do not evaluate to negative or non-integral values. No two equal digits or operators can touch each other in any way. Operators are always placed between the operands.
About: This puzzle type was invented by Anurag Sahay.