In the attached picture there's a symbol I don't understand. To understand additive functional dependency I need to know what the symbol means. Please advice?
It's the symbol where it says: "Suppose that X ⊇ Y and that..."
⊇ = ?
Thanks!
Actually, superset (X is a superset of Y, Y is a subset of X)
bdukes
2010-10-06 13:32:07
http://en.wikipedia.org/wiki/Subset
bdukes
2010-10-06 13:32:34
Thank you! Now I can get back to actually learning the rest..
Phil
2010-10-06 13:33:41
Thank you both, of course. Depending on which way you read the text..
Phil
2010-10-06 13:34:36
@bdukes, x is a superset of y, and y is a subset of x are synonymous, and depending on your background in the subject, subset is usually the preferred way to state the relationship.
AaronM
2010-10-06 13:36:38
Of course! That was silly of me.
TRiG
2010-10-06 13:38:16
+4
A:
This symbol is used in set theory to say that X is a superset of Y, ie. All elements of Y are contained within X. Note that X could be equal to Y in this meaning. Without the underlining on the symbol Y would be a strict subset of X meaning they cannot be equal
chillysapien
2010-10-06 13:31:49
+3
A:
It means "X is a superset of Y". The subset symbol is the same but flipped horizontally.
Frédéric Hamidi
2010-10-06 13:32:03