Proof: Byte 3 Stays the Same 6
Let's prove the following theorem:
if the following are true:
- subtract immediate instruction with dst: 1 src: 1 and immediate: 1 at 12
- the PC at time 6 = 12
- value of cell 3 at time 6 = 3
then value of cell 3 at time 7 = 3
Proof:
Given
1 | subtract immediate instruction with dst: 1 src: 1 and immediate: 1 at 12 |
---|---|
2 | the PC at time 6 = 12 |
3 | value of cell 3 at time 6 = 3 |
# | Claim | Reason |
---|---|---|
1 | not (3 = 1) | not (3 = 1) |
2 | value of cell 3 at time (6 + 1) = value of cell 3 at time 6 | if subtract immediate instruction with dst: 1 src: 1 and immediate: 1 at 12 and the PC at time 6 = 12 and not (3 = 1), then value of cell 3 at time (6 + 1) = value of cell 3 at time 6 |
3 | 6 + 1 = 7 | 6 + 1 = 7 |
4 | value of cell 3 at time (6 + 1) = value of cell 3 at time 7 | if 6 + 1 = 7, then value of cell 3 at time (6 + 1) = value of cell 3 at time 7 |
5 | value of cell 3 at time 7 = value of cell 3 at time 6 | if value of cell 3 at time (6 + 1) = value of cell 3 at time 7 and value of cell 3 at time (6 + 1) = value of cell 3 at time 6, then value of cell 3 at time 7 = value of cell 3 at time 6 |
6 | value of cell 3 at time 7 = 3 | if value of cell 3 at time 7 = value of cell 3 at time 6 and value of cell 3 at time 6 = 3, then value of cell 3 at time 7 = 3 |
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