The Internal Revenue Code is notoriously complex, both substantively and structurally. This article examines one source of structural complexity in the Internal Revenue Code: dependency among sections that stems from defined terms. In particular, the article examines what it terms the problem of “definitional scope”: when the structure of the Code leaves unclear to what a term refers. The article uses the problem of definitional scope as a case study to suggest that those who draft tax legislation should formalize proposed statutory language — translate it into logical terms — prior to its enactment. Formalization could help drafters avoid unintentional ambiguity and refine the language used in the statute; it could provide helpful guidance for those wishing to interpret the statute; and, most importantly, it could help move the law closer to legibility by a computer — that is, it could help on the journey to actual legal artificial intelligence
