  Motivated by the Fredholm theory on the standard Hilbert module over an
unital C*-algebra introduced by Mishchenko and Fomenko, we provide a new
approach to axiomatic Fredholm theory in unital C*-algebras established by
Keckic and Lazovic in [28]. Our approach is equivalent to the approach
introduced by Keckic and Lazovic, however, we provide new proofs which are
motivated by the proofs given by Mishchenko and Fomenko.

Operator Algebras;Functional Analysis