can I get a help for this problem, please?

2.4.2. Let D = {0, 1} and let T = D D D. A correct addition of two numbers in binary notation can be pictured as a string in T" if we think of the symbols in T as vertical columns. For example, 0 1 0 1 +01 1 0 1 0 1 1 would be pictured as the following string of four symbols. 8000 Show that the set of all strings in T" that represent correct additions is a regular language