NOT.1:4.1 - Choose an operation and the conditions for performing it

Describe what the user starts with, what they do and what they need to obtain. Prefer a question such as “after exchanging these two operations, what changes in the result?” to an aim such as “make the notation intuitive”. The former exposes what an expression must support.

Specify the preparation and access on which the operation relies. A mathematician may use established algebraic conventions; a performer may recognize a learned gesture; a program may receive only serialized text. An AI agent’s access to a rendered page, a text extraction and an editor’s internal structure are different conditions. Include the context that is actually available, rather than assuming that every reader receives the designer’s view.

For a small task, one operation is enough to begin. If the notation will be used for a family of operations, choose cases that exercise materially different demands. For example, interpreting a completed expression and changing a shared component can need different support. Do not turn this selection into an inventory of every conceivable use.