Construct a compound proposition that asserts that every cell of a 9 × 9 Sudoku puzzle contains at least one number

Question

Here is a problem from Kenneth Rosen's Discrete Mathematics and its Applications, Section 1.3

Construct a compound proposition that asserts that every cell of a 9 × 9 Sudoku puzzle contains at least one number.

This is a homework problem and I am not expecting a complete answer.

Answer 1

p is Sudoku puzzle and
for all c, (c is cell and c in p
implies exists n with (n is digit and n in c))