Abstract: Aspects of the invention relate generally to software, and more specifically to one or more specifically to software development, FIOSM creation, comparison and subsumption in a software environment and software quality assurance. An exemplary embodiment includes the processes of: (i) designing and verifying that a computer language can completely and correctly generate a Finite Input-Output Semantic Model (FIOSM); and (ii) generating, typically using automation, a FIOSM for a program or system of several programs written in a FIOSM-compatible language.