The thesis of this dissertation is that formal definitions of the syntax and semantics of computer languages are needed. This dissertation investigates two candidates for formally defining computer languages: (1) the formalism of canonical systems for defining the syntax of a computer language and its translation into a target language, and (2) the formalisms of the l-calculus and extended Markov algorithms as a combined formalism used as the basis of a target language for defining the semantics of a computer language.