Abstract: This document discloses methods of acquiring a 3D map of an area with multiple heights. The 3D map may include tiles, each of which provides ground height information for one or more of the plurality of levels. A grid corresponding to the 3D map is generated. The grid may divide each of the plurality of tiles into a plurality of cells, The grid may include: (a) a unique index assigned to each of the plurality of cells, in which the unique index is convertible to an index of a tile of the 3D map in which that cell is included, and (b) a plurality of gridlets associated with each of the plurality of cells, wherein a number of the plurality of gridlets associated with a cell is equal to a number of height levels represented by a tile of the 3D map in which that cell is included.

Abstract: The invention relates to a method for checking and/or transformation of a computer program present in a programming language which supports first-class functions and in which a type check of the program or of at least a part of the program is performed in order to assign a type to each expression of the program or part of the program, the type consisting of a base type and a binding time. The set of base types comprises at least base types for describing simple values and a function type for describing functions, and the set of binding times comprises at least one static binding time and one dynamic binding time, and a function type is only accepted during the type check together with the static binding time.

Abstract: The invention relates to a method for checking and/or transformation of a computer program present in a programming language which supports first-class functions and in which a type check of the program or of at least a part of the program is performed in order to assign a type to each expression of the program or part of the program, the type consisting of a base type and a binding time. The set of base types comprises at least base types for describing simple values and a function type for describing functions, and the set of binding times comprises at least one static binding time and one dynamic binding time, and a function type is only accepted during the type check together with the static binding time.