On the syntax and semantics of virtual linguistic terms for information fusion in decision making

•Define the syntax and semantics of virtual linguistic terms (VLTs).•Specify the semantics within inclusive and non-inclusive interpretations.•Provide the theoretical foundation of the computational models based on VLTs.

The virtual linguistic model is a good technique for linguistic decision making and has been widely used in applications including linguistic information fusion. The main purpose of this paper is to define and specify the syntax and semantics of virtual linguistic terms (VLTs) in detail, and then to serve as the theoretical foundation of the computational models based on VLTs. The syntactical rule generates VLTs by a symbolic transformation, and then the semantic rule presents the semantics of VLTs by means of linguistic modifiers. Based on the syntax and semantics, VLTs could be a possible alternative for solving some current challenges of qualitative information fusion in decision making.