An intentional language as the basis of a 3-D spreadsheet design

Intensional logic is concerned with assertions and other expressions whose meaning depends on an implicit context. An intensional language is both a programming language and, at the same time, a formal system based on intensional semantics. It provides users with context-switching operators which allow values from different contexts to be combined without explicit context manipulation. Plane Lucid is an extension of the language Lucid, a language based on intensional logic. The language allows values of expressions in a program to vary in space as well as in time; it provides spatial and temporal operators to combine values from different contexts (or different points in space and time). As an application of Plane Lucid, an intensional 3-D spreadsheet has been designed in which Plane Lucid is the definition language of the spreadsheet. The spreadsheet is considered as a single entity (called the spreadsheet variable) which varies in spatial and temporal dimensions; values of cells in the spreadsheet are values of the spreadsheet variable at different spatial and temporal points.