A Formal Model of Alternative Letter Articulation for Cyrillic Graphemes

This work presents a formal model of an alternative alphabetic input method based on the articulation of Cyrillic graphemes using facial and manual motor components. The model defines a mapping from abstract graphemes to ordered sequences of articulatory operations, parameterized by articulator type, spatial position, orientation, contact characteristics, and temporal extent. The proposed system does not constitute a language, a sign language, or a communication system, and it is not intended to replace spoken speech. It is considered an articulatory layer over an existing written system and may serve as a model for a non-vocal, non-acoustic letter-level input channel in contexts where conventional input modalities are constrained. The complete grapheme inventory and operational realizations are intentionally not disclosed. The publication focuses on the formal structure of the model, its definitions, and the scope of its applicability.