I had to do pretty extensive CF list modifications in one of my projects the other day. To do that, I used the good old Venn diagram metaphor to work with sets and AND, OR, NOT operators – made my life much easier.
Why I’m writing this: while dealing with it, I remembered back to primary school when we were introduced to basic Venn diagrams (for 7 or 8 year olds…) – using a plastic template to draw the Venn sets with red triangles, blue squares or green apples 🙂
And funny enough, they are still available today, you can now even order them online. Exactly the same as 25 years ago – I had the red one 🙂