Evaluating Queries

You can evaluate queries using the PAL Queries Tab. The PAL engine will check that the instances in the knowledge base conform to your queries and the PAL Queries Tab will display any instances that violate them.

To evaluate queries:

1. Go to the PAL Queries Tab and make sure the query(s) you want to evaluate are displayed. See Displaying Queries at the Queries Tab for more information.
2. Tag the queries you want to evaluate by clicking in the Evaluate? column. Tagged queries are shown with a checkmark .
3. Click the Evaluate indicated queries button.
   The PAL engine evaluates the instances of each tagged query. Queries that have instances that meet the query are shown with plusses in the Status column. A red warning sign indicates that there are no instances which satisfy the query. 
4. To see details about a particular query, click on the query to select it. 
   The area at the right of the PAL Queries Tab displays the instances which satisfy the query, grouping them by the name of the variable that they fill in one satisfying occurrence of the query. In some cases, for clarity, you might want to declare a variable which is otherwise unused so that the specific instances that fill that variable will appear when the query is evaluated. Note that if the query has a limit on number of instances (for example, three-articles-not-written-by-person), only the first n instances encountered by the Query engine will be displayed.
   
   
   

You can view the Instance Form for any of the displayed instances by clicking on the instance to highlight it and then clicking the View button at the upper right of the pane.

PAL Queries User Interface/Evaluating Queries

Next: Tracing Query Functions and Predicates

PAL Table of Contents