M.H. Halstead's theory (1977) has been validated for different languages, but Pascal programs seem to fit only partially with the theory. D.B. Johnston and A.M. Lister (1981) first recognized the lack of operators due to the structure of this language and proposed a modification of Halstead's formula. The article confirms their results but suggests a correction to their formula, which is particularly necessary for large programs. Experimental results, obtained by examining about 550 Pascal programs, represent the widest test to date of Halstead theory with regard to Pascal programs.>

The expanding role of database systems is now faced with a new application field, i.e. large image-file management. Composite documents in the Office Automation environment often include images (e.g. graphs, drawings, illustrated or handwritten documents, and so on), as well as alphanumeric and other coded data. Images are stored on mass storage after conversion into a long sequence of bits, performed by scanner devices. Bit-map images are then compressed either using run-length encoding techniques or quadtree-based techniques. The goal of this paper is to show how quadtree-encoded images, which usually require more storage than run-length encodings, can be compressed using a new technique, named P-compression, which is effective for typical Office Automation documents.