 As a result, not only did Principia introduce a wide range of philosophically rich notions (including  propositional function,  logical construction, and  type theory),  it also set the stage for the discovery of crucial metatheoretic results (including those of Kurt Gödel, Alonzo Church, Alan Turing and others). Just as importantly, it initiated a tradition of common technical work in fields as diverse as philosophy, mathematics, linguistics, economics and computer science.