Formal language for the Virtual Geographic Environment

As a new-generation tool for geographic cognition and analysis, the Virtual Geographic Environment (VGE) effectively decreases the difficulty of geographic environment cognition. However, some deeper problems remain in the integration of geographic information and human cognition. This article reviews the relationship between language and cognition, and the formal language for the VGE (VFL) is proposed to solve the problems mentioned above. First, the definition of VFL is given and its characteristics are explained. Second, the construction process of VGE based on VFL is shown. Third, the semantics of VFL are discussed, especially with respect to spatio-temporal relation predications and their functions. VFL’s expression elements are illustrated with a particular focus on classification and representation layers. VFL’s syntax concentrates on the formal model, the rewriting rules and the semantics mapping rules. To narrate VFL’s function and usage in the VGE, two use-cases are identified at different syntax levels: (1) the generation of a thematic point symbol based on the dual semantic structures; and (2) the generation of a virtual indoor environment. Finally, a short summary of the shortcomings of the current VFL is given, and future directions are proposed to facilitate ongoing progress toward forming a comprehensive version of the VGE.