valuation of bonds, the original cost price, minus the AMORTIZATION of
premium (on straight-line basis) to maturity of earlier call feature producing
lowest amortized value.
This is the basis prescribed, for example, by New York State for
all insurance companies for 1967 (amortized values on amortizable securities
and values on the "convention" basis for other securities).
in valuing bonds are required to amortize premium and have the option
of accreting discount.