[SIC\]DIFF Var1|File1 Var2|File2 List the differences between two entities. Each entity can be either a Sic variable name or a GDF file name (images, cubes, UV tables,...). Comparison is made on their headers (if both variables provide a header) and/or their data (if both variables provide a data array). The result of the last comparison (true/false) is saved in the logical variable SIC%DIFF.