If an issue arises between the Participants in respect of the amount payable under clause 1 of this Schedule, then a Participant may by notice in writing to the others, specify the nature of the issue and call for submission of the issue to an Adjudicator to determine it. In the event of a submission of the issue to the Adjudicator, the Adjudicator must determine the amount payable by the Project Owner to the NOPs or the NOPs to the Project Owner (as the case may be) by determining the net sum of the amounts set out in clauses 1(b)(1) to (7) of this Schedule (Determination).