In my research on quantum physics, I also study the book "Student Friendly Quantum Field Theory" by Robert D. Klauber. This led to the question or idea of whether some of the calculations listed could not be facilitated by Mathematica.
As a Mathematica package to support the calculations, Quantum Algebra seemed to me to be suitable - at least somewhat. But some of the mathematical symbols used in the book were not supported by Quantum Algebra. Quantum algebra had to be extended. So an extended application resulted. This extension and what it does should be presented below.
Essentially these are summation, integration and derivation symbols, the operator notation already present in the basic package and the support of matrices. All are supported by appropriate rules for simplification and reshaping - just as you would do manually.