A significant portion of the ANSI/IEEE-854 Standard for Radix-Independent Floating-Point Arithmetic is defined in PVS (Prototype Verification System). Since IEEE-854 is a generalization of the ANSI/IEEE-754 Standard for Binary Floating-Point Arithmetic, the definition of IEEE-854 in PVS also formally defines much of IEEE-754. This collection of PVS theories provides a basis for machine checked verification of floating-point systems. This formal definition illustrates that formal specification techniques are sufficiently advanced that it is reasonable to consider their use in the development of future standards. keywords: Floating-point arithmetic, Formal Methods, Specification, Verification. 1 Introduction This document describes a definition of the ANSI/IEEE-854 [3] Standard for Radix-Independent Floating-Point Arithmetic in the PVS verification system (developed at SRI International) [4]. IEEE-854 is a generalization of the ANSI/IEEE-754 [2] Standard for Binary Floating-Point Ari...