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Rule FAQs (Frequently Asked Questions)

 

How can I express 'or' and 'not' in my rules?

My rule model contains certainty factors. Will it automatically make use of them at runtime?

What happens if my rules contain a syntax error?

Do rules chain correctly even if they use text with mismatching case?

How can a rule model represent a fact like 'Weather IS Wet'?

Can I import into InterModeller a set of rules that I've prepared using my word processor?

Why does my model at runtime ask the same question twice?

 

InterModeller Help Contents


 

How can I express 'or' and 'not' in my rules?

You may use these words freely in your rules, but InterModeller does not recognise them as special logical connectives.  Perhaps an indirect approach is useful. For instance, if you want to express the idea that (say) 'pilots are safe if they are lucky or skilful' you could write one rule for each case:

Pilot IS safe IF

Pilot IS lucky .

Pilot IS safe IF

Pilot IS skilful .

If you want to express the idea that (say) 'Pilots are happy if their planes do not crash' you could say 

Pilots ARE happy IF

planes ARE free from crashes .

 

My rule model contains certainty factors. Will it automatically make use of them at runtime?

Yes. InterModeller will spot the certainty factors and automatically select the CF logic mode from the Run/Logic menu command. If a model contains no CF tags and you want to run it in CF logic mode, you must select the menu command manually.

 

What happens if my rules contain a syntax error?

You will get an error message and InterModeller will highlight some of your rule text to indicate the part of the window that generated the error. A model with a syntax error will not run.

 

Do rules chain correctly even if they use text with mismatching case?

Yes. InterModeller is not case-sensitive.

 

How can a rule model represent a fact like 'Weather IS Wet'?

A rule model can define facts using the FACT keyword, so you may write FACT Weather IS Wet.

 

Can I import into InterModeller a set of rules that I've prepared using my word processor?

Yes, just paste them into a rule window via the clipboard. 

 

Why does my model at runtime ask the same question twice?

During a consultation, InterModeller keeps track of questions and answers. It will never ask exactly the same question twice. Check whether you have accidentally mistyped some text in your model and make sure that you re-use all symbols consistently. If you use the phrase 'Height' in one part of your model and 'Hieght' in another, InterModeller will assume these refer to different concepts and may ask questions that look like duplicates.