Description: An interval-closed set A in a total order has the same subspace topology as the restricted order topology. (An interval-closed set is the same thing as an open or half-open or closed interval in RR , but in other sets like QQ there are interval-closed sets like ( _pi , +oo ) i^i QQ that are not intervals.) (Contributed by Mario Carneiro, 9-Sep-2015)
Ref | Expression | ||
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Hypotheses | ordtrest2.1 | |
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ordtrest2.2 | |
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ordtrest2.3 | |
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ordtrest2.4 | |
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Assertion | ordtrest2 | |