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annotate 3-Prolog/day1-self-study.pl @ 73:74976fddd25f

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Ignore Erlang binary files and remove existing ones
author IBBoard <dev@ibboard.co.uk>
date Sat, 03 Feb 2018 19:52:45 +0000
parents 96e77f914f9b
children
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3a20e8b49bc4 Write some self-study code with an additional stretch rule to find collaborations
IBBoard <dev@ibboard.co.uk>
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1 % Make a KB of books and authors and query it.
3a20e8b49bc4 Write some self-study code with an additional stretch rule to find collaborations
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2 book(the_long_earth).
3a20e8b49bc4 Write some self-study code with an additional stretch rule to find collaborations
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3 book(night_watch).
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4 book(science_of_discworld).
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3a20e8b49bc4 Write some self-study code with an additional stretch rule to find collaborations
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5 book(lord_of_the_rings).
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6 book(route_666).
3a20e8b49bc4 Write some self-study code with an additional stretch rule to find collaborations
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7 book(krokodil_tears).
3a20e8b49bc4 Write some self-study code with an additional stretch rule to find collaborations
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8 author(terry_pratchett).
3a20e8b49bc4 Write some self-study code with an additional stretch rule to find collaborations
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9 author(stephen_baxter).
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10 author(jack_cohen).
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11 author(ian_stewart).
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3a20e8b49bc4 Write some self-study code with an additional stretch rule to find collaborations
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12 author(jrr_tolkein).
3a20e8b49bc4 Write some self-study code with an additional stretch rule to find collaborations
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13 author(jack_yeovil).
3a20e8b49bc4 Write some self-study code with an additional stretch rule to find collaborations
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14 wrote(terry_pratchett, the_long_earth).
3a20e8b49bc4 Write some self-study code with an additional stretch rule to find collaborations
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15 wrote(stephen_baxter, the_long_earth).
3a20e8b49bc4 Write some self-study code with an additional stretch rule to find collaborations
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16 wrote(terry_pratchett, night_watch).
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2bbb377ddeb0 Add more examples, more thoughts and a three-argument "collaborated" rule
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17 wrote(terry_pratchett, science_of_discworld).
2bbb377ddeb0 Add more examples, more thoughts and a three-argument "collaborated" rule
IBBoard <dev@ibboard.co.uk>
parents: 55
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18 wrote(jack_cohen, science_of_discworld).
2bbb377ddeb0 Add more examples, more thoughts and a three-argument "collaborated" rule
IBBoard <dev@ibboard.co.uk>
parents: 55
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19 wrote(ian_stewart, science_of_discworld).
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3a20e8b49bc4 Write some self-study code with an additional stretch rule to find collaborations
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parents:
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20 wrote(jrr_tolkein, lord_of_the_rings).
3a20e8b49bc4 Write some self-study code with an additional stretch rule to find collaborations
IBBoard <dev@ibboard.co.uk>
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21 wrote(jack_yeovil, route_666).
3a20e8b49bc4 Write some self-study code with an additional stretch rule to find collaborations
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22 wrote(jack_yeovil, krokodil_tears).
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23
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24 collaborated(Author1, Author2, Book) :- wrote(Author1, Book), wrote(Author2, Book), Author1 \== Author2.
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26 collaborated(Author1, Author2) :- collaborated(Author1, Author2, Book).
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3a20e8b49bc4 Write some self-study code with an additional stretch rule to find collaborations
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27 % collaborated(terry_pratchett, stephen_baxter). returns true, but collaborated(Author1, Author2). just says "no", as does
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2bbb377ddeb0 Add more examples, more thoughts and a three-argument "collaborated" rule
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28 % collaborated(terry_pratchett, OtherAuthor). - for some reason it isn't filling in answers. It does, however, correctly
2bbb377ddeb0 Add more examples, more thoughts and a three-argument "collaborated" rule
IBBoard <dev@ibboard.co.uk>
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29 % say that Pratchett never collaborated with Pratchett.
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3a20e8b49bc4 Write some self-study code with an additional stretch rule to find collaborations
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30 %
3a20e8b49bc4 Write some self-study code with an additional stretch rule to find collaborations
IBBoard <dev@ibboard.co.uk>
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31 % If I remove "\+(Author1 = Author2)" then it successfully returns stephen_baxter for terry_pratchett but also returns
3a20e8b49bc4 Write some self-study code with an additional stretch rule to find collaborations
IBBoard <dev@ibboard.co.uk>
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32 % Pratchett himself as a valid answer as well.
3a20e8b49bc4 Write some self-study code with an additional stretch rule to find collaborations
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33 %
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34 % wrote(terry_pratchett, Book). works to return all books by an author, though.
2bbb377ddeb0 Add more examples, more thoughts and a three-argument "collaborated" rule
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35 %
2bbb377ddeb0 Add more examples, more thoughts and a three-argument "collaborated" rule
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36 % However, having added a three-argument version, it can correctly identify the books that someone collaborated on if
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49cb2f7af872 Fix the Day 1 collaboration problems
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37 % you supply both authors but it won't supply an author when given one author and the book title.
49cb2f7af872 Fix the Day 1 collaboration problems
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38 %
49cb2f7af872 Fix the Day 1 collaboration problems
IBBoard <dev@ibboard.co.uk>
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39 % On tracing this and the W&G example then it seems that "\+(…)" doesn't play nicely with variables. The W&G examples
49cb2f7af872 Fix the Day 1 collaboration problems
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40 % worked because we only asked "are these two people friends" questions, not "who is friends with" questions.
49cb2f7af872 Fix the Day 1 collaboration problems
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41 %
49cb2f7af872 Fix the Day 1 collaboration problems
IBBoard <dev@ibboard.co.uk>
parents: 57
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42 % What we actually need is "\==" (not equal/equivalent). Also, we need to put it at the end so that Author1 and Author2 have
49cb2f7af872 Fix the Day 1 collaboration problems
IBBoard <dev@ibboard.co.uk>
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43 % been assigned by that point.