Scenes and what each shows

#One point per canvas

A scene's canvas makes one point at a time. The sentence beside it is about one thing, and the reader takes the canvas as the picture of that thing: whatever else stands on it is read as part of the same point, or has to be set aside before they can look. A canvas assembled from everything related to the scene's topic — a graph, a list restating the prose, a display equation, a question that needs none of them — leaves the reader to work out which part the sentence is about.

#What shares a canvas

Several elements share a canvas when they make the point together:

• two graphs set side by side to be compared;
• a figure and the equation it plots;
• a table and the question that reads it;
• a network and the code that builds it.

scene{
    Compound interest multiplies rather than adds, so a balance at a
    fixed rate curves upward.
}[
    equation{
        B(t) = 100 \times 1.05^{t}
    }
    graph{
        curve(expression: 100 * 1.05^x; label: $B(t)$)
    }(
        x domain: [0, 30]
        x axis label: years
        y axis label: balance
    )
]

A question is canvas content, and shares a canvas only with the visual it needs — Questions & tasks.

#A second idea as a second scene

A second idea is a second scene. Within a scene a step can bring a mark in and a cue can take it out again, but neither a canvas environment nor a table can be cued: cue takes neither, so once on the canvas they stand for the whole scene. Where one point has to give way to the next, splitting the scene is the way to clear the canvas.

#A scene without a detail

A scene's detail is optional. A scene that states a definition, sets a task or draws a conclusion may carry none. A detail filled because the slot is there — a list restating the paragraph beside it — gives the reader the same sentences twice.

#Headings and scene breaks

A heading marks a new section of the argument, not a new scene. Splitting a scene in two leaves both halves in the section they were in, so the second half takes no heading of its own. One written anyway divides the argument into parts it does not have, and a reader scanning the headings for its subjects meets one that names half a subject.