11 lines
189 B
Text
11 lines
189 B
Text
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import data.finset.basic
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open finset
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check ∅ -- o.k.
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check λs t, subset s t -- o.k.
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check λs t, s ⊆ t -- fixed
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infix `⊆`:50 := subset
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check λs t, s ⊆ t
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