Prove the equivalence between the retrospective and the prospective method by using the commutation symbols for 1 specific type of insurance with NSP or NPP premiums For example for a pure endowment...

Prove the equivalence between the retrospective and the prospective method by using the commutation symbols for 1 specific type of insurance with NSP or NPP premiums

For example for a pure endowment NSP, a pure endowment NPP, a whole life insurance NSP or a whole life insurance NPP...