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Okay. I have a problem maybe someone can help me with. The article says: "If the machine prints NPRNPR, it has printed a false statement. But if the machine n
by dbz 17y ago
Okay. I have a problem maybe someone can help me with.
The article says:
"If the machine prints NPRNPR, it has printed a false statement. But if the machine never prints NPRNPR, then NPRNPR is a true statement that the machine never prints."
This part seems logically true:
"If the machine prints NPRNPR, it has printed a false statement." It seems logically true, and I wont say why because I view it as obvious =/
This part seems logically false:
"if the machine never prints NPRNPR, then NPRNPR is a true statement" I don't understand the logic of "If it is not printed, it is true." I was under the impression that the only true statement was "If it prints, then it is true", and of course the contrapositive: "If it is not true, it doesn't print". The statement taken from the article is NOT the contrapositive. It is the inverse, and because the converse of a statement is not always true, the inverse is not always true because the inverse is always equal to the converse.
"if the machine never prints NPRNPR, then NPRNPR is a true statement" That statement is the inverse of the original if-then statement, and the inverse/converse is FALSE because it allows opportunities which violate the original if-then statement.
I logically concluded that the statement in the proof:
"if the machine never prints NPRNPR, then NPRNPR is a true statement" is a false statement. And therefore the proof is incorrect.
Okay. If I am wrong, can someone please tell me where?
- evo 17y agoThe truth of the statement does not derive from being an inverse, converse, or contrapositive of the statement before it. Rather, it is inferred from what we defined "NPR" to mean. Since "NPR" is defined as true if what follows it is never printed twice in succession, and "NPRNPR" is never printed as a given, then "NPRNPR" as a statement is true.
- dbz 17y agoAh. Wonderful. I see now. Thanks a lot =]