Monday 26 March 2007

"Countable" versus "Finite"

I noticed use of the word "countable" in the description of the deductive system in the 'Computing ideal sceptical argumentation' paper:

"... countably many sentences..."
"... a countable set of inference rules..."

Is this different to the word "finite"?


Yes. The set of natural numbers is countable but infinite. The set of real numbers is not even countable.

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