Ernst Schröder

…the late 19th-century German mathematician Ernst Schröder and in Löwenheim (in particular, in his paper of 1915). The basic tools and results achieved in model theory—such as the Löwenheim-Skolem theorem, the completeness theorem of elementary logic, and Skolem’s construction of nonstandard models of arithmetic—were developed during the period from 1915…

…the German mathematician and algebraist Ernst Schröder. His first work, Der Operations-kreis des Logikkalkuls (1877; “The Circle of Operations of the Logical Calculus”), was an equational algebraic logic influenced by Boole and Grassmann but presented in an especially clear, concise, and careful manner; it was, however, intensional in that letters…

…George Boole, and somewhat later Ernst Schröder in Germany, were instrumental in transforming logic from a purely metaphysical into a mathematical discipline. They also added to the growing realization of the immense potential of algebraic thinking, freed from its narrow conception as the discipline of polynomial equations and number systems.