This puzzle consists completely of binary numbers, so all the characters needed to fill in the squares will be 0s or 1s. The crossword is a 4x4 square grid, so all numbers will be written in binary, with 4 digits; e.g., 1 will be 0001, 2 will be 0010, and 4, 0100. The NOT operation changes all 0s to 1's and all 1s to 0s; e.g., NOT(0110) is 1001 and NOT(1010) is 0101.

Rows:
1. "2 Down" x 2
2. A triangular number
3. The cube of ("4 Down" - 2)
4. "3 Across" + "3 Down"

Columns:
1. NOT "2 Across"
2. NOT "1 Across"
3. "2 Across" x 2
4. "4 Across" - "1 Across"

To start, consider 1 across and 2 down. A binary number times 2 must end in 0. NOT 0 is 1; 1x2=10, NOT 10 is 01, 01x2=010, NOT 010 is 101, 101x2 is 1010, NOT 1010 is 0101, 0101X2=1010 so that is the only answer.

2 Across is NOT 1 down, so it must be 01__, and the only triangle number between 4 and 7 is 6 or 0110. NOT this is 1001 and twice this is 1100. 4 down is 001_, so 3 across is 0001 and 4 down is 0011, which gives the following grid:

1010'
0110
0001
1101

Posted by Gamer on 2005-11-04 00:56:35