The assessee sold cylinders to two entities that were returned during the relevant year. Before selling the cylinder, they formed part of the block of assets; consequently, on sales, they were reduced from the block of assets. On return, they would become part of the asset block. Hence, the assessee would be eligible for depreciation on the asset (cylinder) that will be added back to the asset block during the year under consideration. (AY. 2011-12,  2013-14)