Henry --

At 09:02 AM 2/7/2005 +0100, you wrote:
I am looking for a way to state that a relation is an equivalence relation.

Here is a way of doing that using rules:
some-item is used in the equivalence relation
------------------------------------------------
that-item is related by equivalence to that-item



some-item1 is related by equivalence to some-item2
--------------------------------------------------
that-item2 is related by equivalence to that-item1



some-item1 is related by equivalence to some-item2
that-item2 is related by equivalence to some-item3
------------------------------------------------
that-item1 is related by equivalence to that-item3



this-item1 is related by equivalence to this-item2
==================================================
  A                                      B
  B                                      C



some-item1 is related by equivalence to some-item2
--------------------------------------------------
that-item1 is used in the equivalence relation



some-item1 is related by equivalence to some-item2
--------------------------------------------------
that-item2 is used in the equivalence relation

The first three rules state that the relation is reflexive, symmetric, and transitive, respectively. 

Next is a table saying that [A B] and [B C] are in the relation.

You can run these rules by pointing a browser to www.reengineeringllc.com  and selecting the example called EquivalenceRelation1 .

(Non commercial use of the system is free.)

HTH,  -- Adrian


INTERNET BUSINESS LOGIC (R)
www.reengineeringllc.com

Adrian Walker
Reengineering LLC
PO Box 1412
Bristol
CT 06011-1412 USA

Phone: USA 860 583 9677
Cell:    USA  860 830 2085
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