If in accordance with the recognition principle in paragraph 21 an entity recognises in the
carrying amount of an asset the cost of a replacement for part of an intangible asset, then it
derecognises the carrying amount of the replaced part. If it is not practicable for an entity to
determine the carrying amount of the replaced part, it may use the cost of the replacement as
an indication of what the cost of the replaced part was at the time it was acquired or internally
generated.