Lawsky: Reasoning With Formalized Statutes — The Case Of Capital Gains And Losses

Sarah B. Lawsky (Northwestern; Google Scholar), Reasoning with Formalized Statutes: The Case of Capital Gains and Losses, 43 Va. Tax Rev. 361 (2024):

This article formalizes sections of the Internal Revenue Code — that is, represents them symbolically — and then reasons with these formalizations algebraically, graphically, and, in a novel approach for U.S. legal scholar-ship, using a computer program that proves theorems. Reasoning with the formalizations reveals previously overlooked errors in the statute, demonstrates equivalence between the actual law and facially dissimilar administrative implementations of the law, and uncovers technical corrections in these administrative implementations that the Internal Revenue Service has not openly acknowledged. The article thus shows how reasoning with formalized statutes leads to insights that may be otherwise obscured by the law’s complexity.

Conclusion
This article has shown another advantage of formalizing law: formalized law can be reasoned upon, either algebraically or graphically. As the article has shown, such reasoning can unearth errors within statutes and provide concise, reliable justifications of restatements or implementations of the law. This article has created the reasoning nonmechanically and has also shown that reasoning such as that presented in this article can be implemented computationally.