On 30 September, Ardane SA eliminates 180 jobs, which is a curtailment of its defined benefit plan. At the last reporting date, the obligation was 5,150,000 and the assets 4,700,000. On 30 September, before the curtailment, using current actuarial assumptions and fair value of assets, the obligation is 5,400,000 and the assets 4,650,000. The asset ceiling is not relevant (case facts). Write a short note that sets out the order of the steps and the starting values for determining the effect of the curtailment, distinguishing rule, case facts and conclusion.