A display child format command has the form

<[?]:[prompt]:<child attributes>>

which has two text slots and a term slot.

Let's consider an instance of this operator in which the attributes-slot is filled by "*", indicating no parenthesizing. When this slot is filled by "*", that part is not shown, so we can have an instance looking like this: <x:int>.

For example, here's what the format command <x:int> means:

Display the string or term matching the display-scheme metavariable named "x" in the model.

But if the thing matching the meta-variable is an empty slot, display the string "int" instead, as a prompt.

Do not generate parentheses around the display of this child.

The slot attributes are mostly used for control of parenthesization, which is explained in doc for parentheses.

To read about creating and editing display child format commands, doc for display form dfchild editing.

doc for display form formats IF YOU CAN SEE THIS go to /sfa/Nuprl/Shared/Xindentation_hack_doc.html