Set off of losses allows adjustment of a source loss against income from another source under the same head of income. Set off of losses permits an assessee to adjust a net loss arising from one source against income from any other source under the same head of income, subject to statutory exclusions. Losses from short-term capital assets may be set off against income computed for other capital assets under comparable computation, and losses from non-short-term capital assets may be set off against income from other non-short-term capital assets.