Ch.1 Set Theory Flashcards
“And”
Has to be in both sets
“Or”
In either set or in both sets
whole numbers
Include 0 as well as natural
numbers (1,2,3,4,5,6…)
Natural numbers
1,2,3,4,5,6..
Universal set
Everything
Subset
A group within the universal set or within its self
EVERY SET IS A SUBSET OF ITSELF
The sign for subset is a “C” w longer extenders
Empty set
Is a subset of every set.
The signs for empty set is “O” w a line through it or { }
Complement of a set
Everything that is the opposite to a set
The sign is the letter of the set w a line ontop or “A’ “
(Ex. The complement of a set A is the set of all elements in the universal set that are not in set A).
Intersection of sets
Things both sets have *just the ones that match
“A and B”
“A (upside down U) B”
Union of sets
Everything *in either set or in both
“A or B”
“A U B”
Disjoint sets
No elements in common
(The intersection of the two sets is the empty set.)
How to remember “U” and “upside down U”
“Upside down U” = and (the matching ones)
“U” = union (everything)
Sign for subset
Side ways C w longer arms/extenders
Element sign identification
q
(Not in brackets)
Subset identification
{q}
