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doc-src/Tutorial/Datatype/assoc
author wenzelm
Mon, 02 Oct 2000 14:59:04 +0200
changeset 10128 98ddd0138cbf
parent 5851 15ce4c1c8313
permissions -rw-r--r--
delcongs weak_case_congs;
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
5851
15ce4c1c8313 New section on advanced datatypes.
nipkow
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consts   assoc :: "('key * 'val)list => 'key => 'val option"
15ce4c1c8313 New section on advanced datatypes.
nipkow
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primrec "assoc [] x = None"
15ce4c1c8313 New section on advanced datatypes.
nipkow
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        "assoc (p#ps) x =
15ce4c1c8313 New section on advanced datatypes.
nipkow
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           (let (a,b) = p in if a=x then Some b else assoc ps x)"
isabelle