"The Proof in the Code is a rare achievement: a deeply informed account of modern mathematics and computer science that is also genuinely exciting to read. Kevin Hartnett transforms work in a famously dense domain into a lucid and compelling narrative about how we decide what to trust, in both machines and ourselves. This is science writing at its best: technically precise, conceptually ambitious, and consistently accessible." —Seth Mnookin, author of The Panic Virus

“The Proof in the Code is about the people building a new way of creating mathematics, their ambitions, their uncertainties, their false starts and long leaps. Highly recommended.” —Jordan Ellenberg, author of How Not to Be Wrong 

"Kevin Hartnett is one of today's finest chroniclers of math. With marvelous clarity and narrative flair, he introduces us to the computer-verified proof, the drama behind it, and the people reimagining what math can be." —Steven Strogatz, acclaimed Cornell mathematician, New York Times bestselling author of Infinite Powers, and co-host of The Joy of Why podcast

"Lean is one of the most important things happening to math right now—future generations may come to regard it as the Euclid’s Elements of our time. In The Proof in the Code, Kevin Hartnett perfectly captures the unlikely story of Lean’s birth and development." —Grant Sanderson, creator of 3Blue1Brown

"I loved this weird and wonderful book! You don’t need to like math—or understand code—to grasp why this story matters. The Proof in the Code, written by the one person with the perspective to connect mathematicians, engineers, and the rise of AI, reveals why a technical idea hiding in plain sight could determine whether the machines we build will ever deserve our complete trust." —Amy Webb, author of The Big Nine