Free public beta until December 4, 2026: every course is open, no card needed. After that, the first chapter of each course stays free and full access is a one-time $39 ($19 for up to 100 founding members chosen for helpful feedback). Your progress is kept. How the beta works

binding

The link between a name and a value.

A binding associates a name (or a pattern) with a value; let creates bindings.

Examples

let (x, y) = (3, -2); makes two bindings at once: x to 3 and y to -2.