2020-05-19 12:57:09 +02:00
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input: n -> integer.
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output: prime/1.
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assume: n >= 1.
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2020-05-28 07:06:19 +02:00
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spec: forall X (prime(X) -> exists N (X = N)).
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spec: forall N (prime(N) <-> N > 1 and N <= n and not exists I, J (I > 1 and J > 1 and I * J = N)).
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2020-05-19 12:57:09 +02:00
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2020-05-28 07:06:19 +02:00
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lemma(backward): forall N (composite(N) <-> N > 1 and N <= n and exists I, J (I > 1 and J > 1 and I * J = N)).
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