Describing input field in ArcMap Field Calculator window?

Question

A few days ago I was answering Comparing two fields and printing result as 1 (if number matches) or 0 (if not) using Python Parser of ArcGIS Field Calculator?

When describing the process required to get the result using the Codeblock I talked about the "Pre-Logic Script Code", but then didn't know what to call the next box in the window, so I just said

and in the bottom section enter e

What is that bottom section actually called, so I can use the right term?

[What do I call the circled field?]

• FelixIP: Function call box? Guessing...

Answer 1

I've always referred to the bottom box as the "Expression Box". In fact if you look at the help, it is referred to as an "expression". For example:

In the tool dialog box, an expression can be entered directly into the Expression parameter, or interactively built using the Field Calculator.

• PolyGeo: I just call it the expression too

Answer 2

This is simply called "Expression". And you can refer to it by saying

Provide definition in Pre-Logic Script Block and then Use checksum( !Numbers!,!data_all! ) as expression