Mechanisms are provided for efficiently detecting segments for deduplication. Based on inner erasure position information IERS supplied from an inner erasure information generating circuit, the received value and a priori probability information selection circuit replaces a position where no coded output exists due to puncture or the like with a symbol whose likelihood is \u201c0\u201d. Responsive to a diagnostic article a servicer interface may selectively output textual indicia included in service manuals.