- #1
bobby2k
- 127
- 2
Homework Statement
This question may sound weird, but please bear with me.
Let's say that you are a dog, and you think to yourself.
"All cats have four legs, I have four legs, therefore I am a cat."
Obciously this is wrong because even though all cats have four legs, there are more creatures that have four legs.
But how would we write this in terms of logic? That is in terms of statements and the connectives → ,[itex]\wedge,\vee[/itex]?
The Attempt at a Solution
My attempt is that I define a predicte:
F(x) = "x have four legs".
The predicate C(x) is "x is a cat".
Then I say that statement A is:
[itex]\forall[/itex]x[C(x)→ F(x)]
statement B is:
F(I), that is "I have four legs".
Statement D is:
C(I) "I am a cat"
Now how can I see technically that
A[itex]\wedge[/itex]B → D is false?
This last step I can't get to.