"One of our preset" preset refers to the accumulation of any gathering, called M, all access the same unit object named different m (called "members" of M) according to our understanding, or according to our ideas.
The "set" we mean a set of collectors collect any. Where M is a unit of the same name. The object called m different. (Called "members" of M), according to our understanding. Or follow our thoughts
By "set" set one. We mean the accumulation gather at the M name that is the same unit as a whole, of objects called M is different. (which is called a "member" of the M) according to our understanding, or according to our ideas.