File talk:Provinces and Countries in Ireland Euler Diagram.svg

I've added an annotation where the diagram may be in error. It shows that there are parts of Ulster which are neither part of the Republic of Ireland nor part of Northern Ireland. Rybec (talk) 15:41, 19 March 2014 (UTC)

This Venn diagram does not represent reality. If we represent the various territories with the following symbols (arranged alphabetically):

• C = Connaught
• I = Island of Ireland
• L = Leinster
• M = Munster
• N = Northern Ireland
• R = Republic of Ireland
• U = Ulster

then in reality, the following relationships hold:

$C\cup L\cup M\cup U=I$

$R\cup U=I$

However the diagram suggests that

$C\cup L\cup M\cup U\subsetneq I$

$R\cup U\subsetneq I$

The best Venn diagram of the provinces of Ireland and their relation to the national states is the map itself.

Martinvl (talk) 11:17, 23 July 2014 (UTC)

I fixed it - it's an Euler diagram. Mia (commons) (talk) 20:36, 28 July 2014 (UTC)

The argument that I originally gave holds equally for both Venn and Euler diagram. The difference between a Venn Diagram and an Euler Diagram is that a Venn Diagram must show every possible combination of sets, even if they are null sets - for example the intersection between Munster and Connaught. In a Venn diagram null sets are coloured black. In an Euler diagram, null sets are ignored. Martinvl (talk) 19:25, 11 August 2014 (UTC)