Another relation utility
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@ -11,6 +11,7 @@
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relation->hash
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in-relation-domain
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in-relation/grouped
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relation-empty?
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relation-count
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@ -76,6 +77,9 @@
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(define (in-relation-domain r)
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(in-hash-keys (relation-table r)))
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(define (in-relation/grouped r)
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(in-hash (relation-table r)))
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(define (relation-empty? r)
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(zero? (hash-count (relation-table r))))
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