The Term Structure of Expected Cash Flows (TSECF) records expected net cash flows. Purchasing the bond at 102% of par creates an initial cash outflow at $t=0$: $\text{Outflow} = 20 \text{m} \times 1.02 = 20.4 \text{m}$ Over the 7-month horizon, the bank will receive one semi-annual coupon (at 6 months): $\text{Inflow} = 20 \text{m} \times (8\% / 2) = 0.8 \text{m}$ Net cash flow over 7 months = $-20.4 \text{m} + 0.8 \text{m} = -19.6 \text{m}$. Thus, the TSECF decreases by GBP 19.6 million.

The Term Structure of Available Assets (TSAA) tracks assets that can be readily converted to cash. The newly purchased bond becomes an available asset to the bank. Unencumbered bonds are typically recorded in the TSAA at their face/par value (GBP 20 million) reflecting the principal liquidity value added to the pool. Thus, the TSAA increases by GBP 20 million.