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RE: assertion and trigger

From: Wagner, G.R. <G.R.Wagner@tm.tue.nl>
Date: Mon, 4 Feb 2002 00:07:34 +0100
Message-ID: <511BB18E82E9D11188230008C724064603AB0BDF@tmex1.tm.tue.nl>
To: "'Mohammad Ziaul Ahsan '" <hazra@math.buet.edu>, "'www-rdf-rules@w3.org '" <www-rdf-rules@w3.org>
> What is the difference between assertion and trigger?

The term "assertion" normally refers to a logical statement
(or sentence) A that is being entered into the knowledge base 
(for instance, by means of an "assert(A)" command in Prolog),
while the term "trigger" refers either to an event that 
triggers an "event-condition-action (ECA)" rule, or to the 
rule that is being triggered (e.g., in SQL, ECA rules are called
"triggers"). 

Notice that some people, and some vendors, do not strictly
distinguish between the event condition and the logical
(state) condition of an ECA rule. They may use a language
where "assertion"/"condition" is being confused with "trigger".

In RuleML [1], ECA rules are a special case of event-condition-
action-effect rules (also called "reaction rules").

-Gerd

[1] http://www.dfki.uni-kl.de/ruleml/rmt/
Received on Sunday, 3 February 2002 18:07:50 GMT

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