Compression theorem

In computational complexity theory, the compression theorem is an important theorem about the complexity of computable functions. 
The theorem states that there exists no largest complexity class, with computable boundary, which contains all computable functions.
Compression theorem.
Given a Gödel numbering formula_1 of the computable functions and a Blum complexity measure formula_2 where a complexity class for a boundary function formula_3 is defined as
Then there exists a total computable function formula_3 so that for all formula_6
and