Legal fiction deemed: limits on reclassifying prior tax notices to preserve continuity of reassessment procedure. The text explains that a legal fiction (expressed by 'deemed') treats a thing as existing for a definite purpose and must be limited to that purpose; courts give full effect to the fiction by assuming incidental facts and working out consequences only to their logical extent. As an illustration, earlier reassessment notices were reclassified as show-cause notices under the substituted procedural regime to enable continuity of reassessment proceedings, and that reclassification was confined to the temporal window and purpose necessary to maintain that continuity.