Prolog - How do you distinguish between just a string, and a variable? [closed]

Posted by Mr Prolog on Programmers See other posts from Programmers or by Mr Prolog
Published on 2012-04-06T18:22:50Z Indexed on 2012/04/06 23:39 UTC
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database

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prolog

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query

When you are querying a Prolog database, often you will use terms that start with an uppercase letter as your variables. However, let's say that one of the constraints on your query is that a person's location must be "Dallas", and you want to query all the information in the database who meet those specifications. How would do you correctly make sure that Dallas is not interpreted as a variable to store a value in, and is interpreted as a string instead, for usage as a constraint on the query?

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