## Answers

We can use propositional logic to find if the given system specifications are consistent or not.

Let p denotes **"The diagnostic message is not stored in the buffer."** and q denotes **"The diagnostic message is not retransmitted."** statements.

Then the list of propositions can be written as:

1. "The diagnostic message is not stored in the buffer or it is not retransmitted." => **p ∨ q**

2. "The diagnostic message is stored in the buffer." => **¬p**

3. "If the diagnostic message is stored in the buffer, then it is retransmitted." => **¬p→ ¬q.**

We know that

**p q (¬p → ¬q) --------------------------- F F T F T F T F T T T T**

When p is true and q is true, then **p ∨ q is true, ¬p is false and (¬p → ¬q) is true.**

When p is true and q is false, then **p ∨ q is true, ¬p is false and (¬p → ¬q) is true.**

When p is false and q is true, then **p ∨ q is true, ¬p is true and (¬p → ¬q) is false.**

When p is false and q is false, then **p ∨ q is false, ¬p is true and (¬p → ¬q) is true.**

So, the given system specifications are not consistent.