user-defined operators

[Eric Newhuis]

> F `each` [ItemsX, ItemsY].
>
> ...where F is a function of two variables.

Perhaps I could have more clearly expressed this as:

Plot `eachPairOf` [XCoordinates, YCoordinates].

The idea is that one applies Plot over each pair of elements in vectors 
XCoordinates and YCoordinates.

Not everyone wants to view the world as a list of records.  Some 
things, especially very large time-series data sets are best kept as 
columnar to facilitate binary search over key vectors.  But I 
digress...