Expressions for completely and partly unsuccessful batched search of sequential and tree-structured files

A number of previous studies derived expressions for batched searching of sequential and tree-structured files on the assumption that all the keys in the batch exist in the file, i.e., all the searches are successful. Formulas for batched searching of sequential and tree-structured files are derived, but the assumption made is that either all or part of the keys in the batch do not exist in the file, i.e., the batched search is completely or partly unsuccessful.<
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