dedication

To the memory of my mother, Barbara A. Black

(May 6, 1933 – January 20, 2026).

—David

To Lucy. Thank you for inspiring me.

—Joe

@font-face { font-family: 'livebook'; src:url('https://d19npu3b8zepp3.cloudfront.net/assets/fonts/livebook.eot?1.9.0'); src:url('https://d19npu3b8zepp3.cloudfront.net/assets/fonts/livebook.eot?1.9.0') format('embedded-opentype'), url('https://d19npu3b8zepp3.cloudfront.net/assets/fonts/livebook.woff?1.9.0') format('woff'), url('https://d19npu3b8zepp3.cloudfront.net/assets/fonts/livebook.ttf?1.9.0') format('truetype'), url('https://d19npu3b8zepp3.cloudfront.net/assets/fonts/livebook.svg?1.9.0') format('svg'); font-weight: normal; font-style: normal; }