Setting up GMPE Functions

Follow the steps below:

Find the series called "Overall GMP Equalisation Effect" and clone it.
Change name of new series to "GMP Equalisation Payments".
Within the item setup screen, set Admin Payment type to "Pension Payments" it is a PPF pre 97 pension.
Set Actuarial type to "payment of funded benefits".
Set both (first and subsequent node) functions to "GmpE: gmpe_payment_series
Set params to:
raw differences = "Overall GMP Equalisation Effect"
forfeit date = date before which we want to ignore differences, eg 1/1/2014
arrears payment date = some date in the future when we settle the arrears, eg 1/7/2020
accumulate negatives = False for B. True for C1, C2.
market date interest (BofE Base = 8,None = -1) = -1 for B and C1, possibly 8 for C2.
fixed interest = 0.0 for B and C1, possibly something for C2.
Clone the new series and call it "GMP Equalisation Arrears"
Set Admin Payment type to "Pension Payment Arrears" it is a PPF pre 97 pension.
Set Actuarial type to "payment of funded benefits".
Set both (first and subsequent node) functions to "GmpE: gmpe_payment_arrears"
Set params same as "GMP Equalisation Payments".
Add a single Real Number item for the arrears figure for adding to letters, using the "GmpE: gmpe_payment_arrears" function using same params as above.
Add a single Text item for the arrears split into tax years for adding to letters, using the "GmpE: gmpe_payment_arrears_tax_years" function using same params as above. The two extra params are for markdown column headers so you can rename, align, set width etc.

Examples...

Payment calc for B, note arrears payment at 25/5/2020.

Arrears Calc for C2 with no "Crossover", note tax year splits

Arrears calc for C2 with crossover happening before the arrears payment date.

Regular payment calc for C2 with crossover happening after the arrears payment date.

Example of slotting a result from "GmpE: gmpe_payment_arrears_tax_years" into a letter with a simple