Facts and rules are sentences, in prose or in a sentences cell; a datalog cell takes plain ROFL; a natural cell is words Claude turns into a cell, on your own Claude account: Translate, or Cmd/Ctrl+Enter in a natural cell, translates. A cell asks with its lines: ? S lists the answers, never S holds when nothing answers, why S and whynot S explain, excise F asks what moves without a fact, draw graph (or time, table, architecture, heatmap, …) draws. A notebook reads a vocabulary in the front matter of a first prose cell, reads: - rofl:visual/time.rofl.md; without one it reads the graph's. To open a notebook, drop it on the page with the files it reads (or its whole folder), pick them with Open…, or give a link: ?url= a GitHub page or raw link of a .rofl.md, or ?gh=owner/repo/path@ref; the files its reads: and code: name are read beside it. The notebook runs a moment after you stop typing; Cmd/Ctrl+Enter runs now, and so does Shift+Enter in a sentences or datalog cell (in prose and natural cells it is a new line).