There are no prime numbers in column 2.

All numbers are one digit numbers (0-8).

There are no composites in row 2.

Sum of column 1 is less than 8

All numbers in row 2 are odd.

All numbers in columns 2 & 3 and row 3 are Natural numbers.

Numbers in row 3 are even and consecutive.

The sum of the four corners is the same as the sum of the first row

Numbers in row 2 total 13.

No number is used twice.