2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/54926We define quantum field theory by taking the Lagrangian action to be given as a sequence of mathematically well-defined functionals written in terms of operator fields fulfilling given \hbox{local} commutation relations. The renormalized solution fields have a fully defined Fock space expansion and are \hbox{multi-local}; thus Haag's theorem does not apply, i.e., the interaction picture exists. Also, the formalism allows immediately the definition of a wave function and the description of many-body bound-state systems.24 pages, latexHigh Energy Physics - Theorytext