I have a question about using the boundary value analysis.
I know that elements in partitions should be ordered if we want to use boundary value analysis, but it is a little bit confusing to me that in one of my books it is stated that: “Every equivalence class needs to be “compact”. Formally, this means that if any two values a, b belong to a certain class, then necessarily all elements x, such that a<x<b, must also belong to this class.
Informally, we can say that the classes cannot have “holes”.
So, if I understand it correctly, this means that our partition should look like in this way: {1, 2, 3, 4, 5, 6, 7, 8...}, and cannot be in this way: {2, 4, 6, 8, 10...}? Or what does it mean that it “cannot have holes”? Also, on Wikipedia, it is stated that "The test vectors on either side of the boundary are called boundary values.
In practice, this would require that the test vectors can be ordered and that the individual parameters follow some kind of order (either partial order or total order)."
What does partial order mean here with an example?