Oids have been part of many data models; for example, they are called surrogates in Codd , l-values in Kuper and Vardi , or object identifiers in Abiteboul and Hull .
We use oids for the traditional encoding of directed (perhaps cyclic) graphs, but also for the manipulation of sets and for making our query language fully expressive.
An instance consists of "data" in the form of: (1) a finite set of o-values; that is, values containing oids, and (2) a partial function v of oids to o-values, this mapping is the essence of the data model.
Every actor is characterised by: an OID, a type (T-Act, C-Act or R-Act), a behavior (optional in the case of a C-Act) and a name (obligatory in the case of a T-Act).
Predefined types are int, float, string, bool and OID. getValue(...), setValue(...) and select(...) are some T-Act predefined methods.
For instance in method managerName of Figure 2, the instruction getValue('last_name',x) sends the message to the actor it self to get the value of the attribute last_name associated with OID instance x.
This "principal-reduction" method applies only to loans that (1) are acquired by the taxpayer at origination; (2) do not have OID, or have de minimis OID; (3) are not issued at a premium; (4) are not subject to election under Regs.
This requirement avoids the necessity of tracking de minimis OID on individual loans within each category.
Under the principal-reduction method of accounting, if a taxpayer holds a debt instrument with de minimis OID, the taxpayer must include that discount in income as stated principal payments are made.
The answer lies in the third prong of the HYDO definition, significant OID, which exists only if on a "testing date" the amounts included in income exceed the amount of interest actually paid.
Further, it is possible to enhance interest deductions through the creation of an OID, which exists if the issuer is permitted to allocate a part of the debenture's issue price to the bond's exchange feature.
If a CVR is a debt instrument (defined in the OID regulations as a right to deferred payments under a contract), the amount paid in its retirement, in excess of its issue price, is treated as interest income.