Its first volume defines the idea of number as the set of all sets equal to the same size, and postulates the axioms of infinity and reducability, in order to avoid a paradox named for one of the authors.
The twenty-first chapter of this work's first section presents a "general theory of relations," and its introduction argues that its ideas are "more abstract than those familiarly considered in language." This work distinguishes between propositional functions and descriptive functions, and attempts to develop a theory of types. Its first volume defines the idea of number as the set of all sets equal to the same size, and postulates the axioms of infinity and reducability, in order to avoid a paradox named for one of the authors. Attempting to reduce the title discipline to pure logic, FTP, name this work by Alfred North Whitehead and Bertrand Russell
The twenty-first chapter of this work's first section presents a "general theory of relations," and its introduction argues that its ideas are "more abstract than those familiarly considered in language."
{Principia Mathematica}