NEC3 Option A: Arithmetical Error in Compensation Event

The Contractor has submitted a quotation for a Compensation Event. The quotation has been accepted and implemented by the PM.

The implemented quotation has subsequently been discovered to contain an arithmetical error which if corrected, would increase the value of the quotation.

Is the PM obliged to rectify the Contractors arithmetical error and if so, how should this be done?

Any errors can be corrected in subsequent valuations (both parties can do this)

Thank you very much for your prompt response - greatly appreciated.

Just to be clear, are you saying that once a Compensation Event has been implemented its value can be subsequently amended in order to correct an arithmetical error?

Is there a particular clause you could direct me to that would cover this situation?