Reconcilation of Pension Benefit Obligation its, provide, should, status

ishfaque

Hi guys,
I can’t grasp the idea of PBO funded status reconciliation in IRFS.
With GAAP its is straight forwars: Funded Status (Asset/Liab) = FUND ASSETS - PBO.
With IFRS the funded status should also be the same, but the books say that we need to provide reconciliation. How to?
Thanks!