2. Then £a shall be compared with the full amount of the charges payable to the dental practitioner by the patient in respect of services provided under the contract or arrangement ("£b") and–
(a)if £a equals or exceeds £b, there is no charge for the supply of the appliance;
(b)if £a is less than £b, the charge for the supply of the appliance is the lesser of–
(i)£b minus £a, or
(ii)80% of the Statement remuneration for the supply of the appliance.