contingency
Neither a tautology or always false
Disjunctive Syllogism
AorB, have B’, conclude A
Hypothetical Syllogism
A->B, B->C, conclude A->C
Contrapositive Property
(A->B) == (B’->A’)
|A| =
cardinality of the set
How many terms are in the power set of n
2^n
A and B are disjoint if…
Their intersection is the empty set
A x B =
{ (a,b) : a exists in A and b exists in B}
Communitive Property for sets
A union B = B union A
Associative Property for sets
A U (B U C) = (A U B) U C
Distributive Property for sets
A U (B intersect C) = (A U B) intersect (A U C)
Identity property for sets
A U empty = A; A intersect S = A
Complement property for sets
A U A’ = S; A intersect A’ = empty
Demorgans for set
(A intersect B)’ = A’ U B’
Multiplication Principle for sets
|AxB| = |A||B|
Addition Principle for sets
|AUB| = |A|+|B| - |A intersect B|
Subtraction for set
|A-B| = |A| - |A intersect B|
P(n,r) =
n!/(n-r)!
P(n,1); P(n,n); P(n,0)
n;n!;1
C(n,r)=
n!/(n-r)!r!
C(n,0);C(n,1);C(n,2);C(n,n);C(n,n-1)
1;n;n(n-1)/2;1;n
Pascals identity
C(n,k) = C(n-1,k) + C(n-1, k-1)
one to one relation
each point in one set connects to one point in the other set
one to many relation
each point in one set connects to multiple points in the other set
