L Cox

I have made a loss of £5,000 in selling some shares and in a separate account made a gain of £9,100. I also have losses carried forward from last year of £4,500. Box 45 says "only use losses brought forward to reduce gains to the ‘annual exempt amount’ for the year". i.e. £6,000. So is that Box 45 = £3,100 (to bring gain down to £6,000) in which case is Box 46 is £0 (as no tax would be due)? And box 47 (Losses available to be carried forward) apply solely to this year's losses (£5,000) or does it include any unused losses from last year? (£5,000+£4,500-£3,100 = £6,400)