Description: Given a function on the extended reals, its supremum limit is real if and only if two condition holds: 1. there is a real number that is less than or equal to the function, infinitely often; 2. there is a real number that is eventually greater than or equal to the function. (Contributed by Glauco Siliprandi, 23-Oct-2021)
Ref | Expression | ||
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Hypotheses | limsupre3uzlem.1 | |
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limsupre3uzlem.2 | |
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limsupre3uzlem.3 | |
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limsupre3uzlem.4 | |
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Assertion | limsupre3uzlem | |