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comparison 3-Prolog/day1-food.pl @ 52:cbaa3546f3f8

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Add extra thought on why you sometimes get "no" and sometimes "yes" after variable lists
author IBBoard <dev@ibboard.co.uk>
date Tue, 26 Sep 2017 19:42:02 +0100
parents 178b18b4f9ba
children
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51:178b18b4f9ba 52:cbaa3546f3f8
14 14
15 food_flavour(X, Y) :- food_type(X, Z), flavour(Y, Z). 15 food_flavour(X, Y) :- food_type(X, Z), flavour(Y, Z).
16 % Note: flavour(sweet, What) will return 'yes' and a closed set of answers because it is just all of the facts 16 % Note: flavour(sweet, What) will return 'yes' and a closed set of answers because it is just all of the facts
17 % but "food_flavour(What, meat)" will return answers and then say 'no', because it hasn't been given a flavour() 17 % but "food_flavour(What, meat)" will return answers and then say 'no', because it hasn't been given a flavour()
18 % fact for "ritz"/"cracker". 18 % fact for "ritz"/"cracker".
19 % This doesn't explain why "food(What, meat)" returns "no" after spam and sausage, though. 19 % This doesn't explain why "food(What, meat)" returns "no" after spam and sausage, though. Maybe because there's
20 % flavour(savoury, meat) so Prolog knows savoury is associated with meat but doesn't know whether it is in a food()
21 % fact without more processing?