process naming to allow libraries to describe their communication in terms suitable to their own data structures and algorithms, ffl The ability to "adorn" a set of communicating processes with additional user-defined attributes, such as extra collective operations. This mechanism should provide a means for the user or library writer effectively to extend a message-passing notation. In addition, a unified mechanism or object is needed for conveniently denoting communication context, the group of communicating processes, to house abstract process naming, and to store adornments. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 134 CHAPTER 5. GROUPS, CONTEXTS, AND COMMUNICATORS 5.1.2 MPI's Support for Libraries The corresponding concepts that MPI provides, specifically to support robust libraries, are as follows: ffl Contexts of communication, ffl Groups of processes, ffl Virtual topolo...