(1) property which the will makes no attempt to dispose of,
(2) property which is disposed of to persons who predecease the decedent with consequent lapsing of the legacy or devise,
(3) property which is incompletely disposed of, as where the testator creates a life estate without disposing of the remainder, or
(4) a disposition which is ineffective by operation of law rather than one where a specified beneficiary under the will cannot be found.