Proof: Byte 127 Stays the Same 12

Let's prove the following theorem:

if the following are true:
  • subtract immediate instruction with dst: 1 src: 1 and immediate: 1 at 18
  • the PC at time 12 = 18
  • value of cell 127 at time 12 = 2

then value of cell 127 at time 13 = 2

Proof:

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Given
1 subtract immediate instruction with dst: 1 src: 1 and immediate: 1 at 18
2 the PC at time 12 = 18
3 value of cell 127 at time 12 = 2
Proof Table
# Claim Reason
1 not (127 = 1) not (127 = 1)
2 value of cell 127 at time (12 + 1) = value of cell 127 at time 12 if subtract immediate instruction with dst: 1 src: 1 and immediate: 1 at 18 and the PC at time 12 = 18 and not (127 = 1), then value of cell 127 at time (12 + 1) = value of cell 127 at time 12
3 12 + 1 = 13 12 + 1 = 13
4 value of cell 127 at time (12 + 1) = value of cell 127 at time 13 if 12 + 1 = 13, then value of cell 127 at time (12 + 1) = value of cell 127 at time 13
5 value of cell 127 at time 13 = value of cell 127 at time 12 if value of cell 127 at time (12 + 1) = value of cell 127 at time 13 and value of cell 127 at time (12 + 1) = value of cell 127 at time 12, then value of cell 127 at time 13 = value of cell 127 at time 12
6 value of cell 127 at time 13 = 2 if value of cell 127 at time 13 = value of cell 127 at time 12 and value of cell 127 at time 12 = 2, then value of cell 127 at time 13 = 2

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