INTERFACE {{p}}if_med_copay PUBLIC.
  TYPES ty_tier TYPE c LENGTH 1.
  TYPES ty_reason TYPE c LENGTH 10.
  TYPES ty_amount TYPE p LENGTH 9 DECIMALS 2.

  CONSTANTS:
    BEGIN OF c_tier,
      standard TYPE ty_tier VALUE 'S',
      chronic  TYPE ty_tier VALUE 'C',
      exempt   TYPE ty_tier VALUE 'E',
    END OF c_tier.

  CONSTANTS:
    BEGIN OF c_reason,
      ok       TYPE ty_reason VALUE 'OK',
      price    TYPE ty_reason VALUE 'PRICE',
      quantity TYPE ty_reason VALUE 'QUANTITY',
      tier     TYPE ty_reason VALUE 'TIER',
    END OF c_reason.

  TYPES:
    BEGIN OF ty_result,
      copay  TYPE ty_amount,
      reason TYPE ty_reason,
    END OF ty_result.

  METHODS calculate
    IMPORTING iv_price         TYPE ty_amount
              iv_quantity      TYPE i
              iv_tier          TYPE ty_tier
    RETURNING VALUE(rs_result) TYPE ty_result.
ENDINTERFACE.