This article is a close reading of Salvador Elizondo’s “Grünewalda, o una fábula del infinito” (1969), a short story from the collection El retrato de Zoe y otras mentiras. Elizondo purposely mirrors in “Grünewalda” a turbulent chapter in the history of mathematics—the turn of the nineteenth century—when this discipline went through a profound crisis. The article shows how Elizondo skillfully crafts a literary version of a process of arithmetization of writing, as taken from the basics of set theory, and how this process helps to discern the level-changing operators in “Grünewalda” and in all of Elizondo’s texts. Given that mathematical knowledge is merely verbal knowledge, Grünewalda’s life and death problems are syntactic and semantic in principle. Thus, beyond ascribing his rhetoric to a metaphysical sphere, a metamathematical realm is presented as a more adequate depiction of Elizondo’s writing.