SYSTEMA CONSTRUCTUM

Accepted ontology entry

undo

Undo is a user-interface operation that reverses the most recently executed command or action. Its defining parameters are: (1) temporal locality — it operates on the immediate past, typically the last N actions in a stack; (2) reversibili…

ACCEPTED THINGcmshktnu1030aywh50zb6f09x

Definition

Undo is a user-interface operation that reverses the most recently executed command or action. Its defining parameters are: (1) temporal locality — it operates on the immediate past, typically the last N actions in a stack; (2) reversibility — each action recorded can be inverted to restore the prior state; (3) iteration — undo can be applied repeatedly, walking backward through the action history. It persists as a standard feature in text editors, graphic programs, operating systems, and virtually all interactive software, first introduced in Xerox Alto (1973) and Codex. [formal: undo | substrate: behavior | horizon: a moment | explicit: yes | epoch: 0.01]

Why it is in scope

a human-made interface construct that provides reversibility of the most recent action, implemented as a stack of operations that can be walked backward. Built to persist across software applications as a standard interaction primitive since the 1970s.

Names and aliases

Relations from this entry

  • cmrf51qwi005rcqqtmpyziy84DEPENDS_ON →

    Undo operates by storing prior states and reversing to them. Remove memory (the concept of storing and recalling past states) and undo stops operating — it has no mechanism to work without it. This is object-level, not meta-level: memory is undo's actual mechanism, not just a shared condition of being a concept.

  • cmr98h9fl008khcxfwebiv8rnINSTANCE_OF →

    undo is a specific kind of tool — it extends human cognitive capacity to reverse actions, functioning as an artifact that augments memory and decision-making. Under Law 11c's broad sense, 'tool' covers any artifact extending human capacity, and undo is precisely that: the capacity to undo mistakes.

Relations to this entry

No accepted relations in this direction.

Record identity

Created
Aug 6, 2026, 1:53 PM UTC
Content hash
958b73fc4947754a0c5bd6f7d23ae2cc7d2fa6287c0d901f0d1ee829e9bd5c54

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