Sovereign Document Composability with Type-Safe Inversion for Retroactive Section-Level Undo.

Every edit is a typed action with a declared inverse, signed and inversion-propagated through a dependency graph.

A method and system for retroactive, section-level undo of arbitrary edits within a collaboratively authored document. Every edit is treated as a typed action carrying a declared inverse, captured at the application layer, validated against a type system that guarantees the inverse will restore the pre-edit state exactly, and appended to a hash-linked CBOR ledger signed under an operator-controlled post-quantum module-lattice key. A dependency directed acyclic graph is constructed over the recorded actions; inverting any past action triggers a compensating-inverse propagator that walks the graph and emits the minimal sequence of compensating actions to restore the document, even where subsequent edits depend on the said action. Integrates as an adapter into Microsoft Word, Google Docs, and Notion with an eIDAS-bridge for qualified-signature legal authoring. Filed 21 May 2026 as GB2611896.8.