In both rules named “Definitions”, add between the third and fourth bullet points:

* Z is a positive integer of the Executing Investor’s choice, which may not be greater than X.

In both rules named “Restrictions” as well as both rules named “Execution”, change all instances of ‘X’ to ‘Z’.

In the first rule named Execution, change:

Set the Seller’s Order to blank, with the GNDT comment ‘Executing Sell Order’

to

Replace X in the Seller’s Order by X-Z. If X-Z is zero, set it to blank instead.

In the second, change

Set the Seller’s Order to blank, with the GNDT comment ‘Executing Sell Order’

to

Replace X in the Buyers’s Order by X-Z. If X-Z is zero, set it to blank instead.