(1) In this Chapter -
"the residual or scrap value", in relation to a wasting asset, means the predictable value, if any, which the wasting asset will have at the end of its predictable life as estimated in accordance with this section;
"wasting asset" means an asset with a predictable life not exceeding 50 years, but so that - (a) freehold land shall not be a wasting asset whatever its nature and whatever the nature of the buildings or works on that land, (b) "life", in relation to any tangible movable property, means useful life, having regard to the purpose for which the tangible assets were acquired or provided by the person making the disposal, (c) plant (other than plant that is a work of art) and machinery shall in every case be regarded as having a predictable life of less than 50 years, and in estimating that life it shall be assumed that its life will end when it is finally put out of use as being unfit for further use and that it will be used in the normal
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