Description: The interior of the intersection of any pair is equal to the intersection of the interiors if and only if the closure of the unions of any pair is equal to the union of closures. (Contributed by RP, 19-Jun-2021)
Ref | Expression | ||
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Hypotheses | ntrcls.o | |
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ntrcls.d | |
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ntrcls.r | |
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Assertion | ntrclsk13 | |