Chains diagram:

A -- B -- C -- D -- E -- F -- G -- H
           \
             -- D1 -- E1 -- F1
           \
             -- D2 -- E2 -- F2
           \
             -- D3 -- E3 -- F3 -- G3 -- H3 
           \
             -- D4 -- E4 -- F4

Coverage added on this work:

1. coins created in D1 and spent in E1. --> expected result: pass.
2. coins created in E, being spent in D4 --> expected result: reject.
3. coins created and spent in E2, being double spent in F2. --> expected result: reject.
4. coins created in D and spent in E3. --> expected result: reject.
5. coins create in D, spent in F and then double spent in F3. --> expected result: reject.
6. coins created in G and G3, being spent in H and H3 --> expected result: pass.