RAH Flashcards

1
Q

An example that proves a statement false is often called a

A

counterexample

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2
Q

direct approach to proving a conditional of the form “if A then B” starts with the assumption that the antecedent ______________

A

A is true.

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3
Q

is a false statement

A

contradiction

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4
Q

starts out by assuming that the statement to be proved is
false

A

proof by contradiction

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5
Q

another name for proof by contradiction

A

indirect proof

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6
Q

a smallest number for which a case is false

A

minimal counterexample

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7
Q

construct an instance of
the object

A

Constructive approach

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8
Q

where we check that each thing has the stated property.

A

Exhaustive checking

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9
Q

That if the premise is true, then the conclusion must also be true.

A

conditional proof

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10
Q

We’ll simply say that a set is a collection of things called its

A

elements,
members, or objects.

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11
Q

A set with one element is called a

A

singleton

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12
Q

Sets can have other sets as elements
T or F

A

T

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13
Q

The set with no elements is called the

A

empty set or null set

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14
Q

The empty set is denoted by

A

∅ or {}

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15
Q

is a set or not?

x = {1,2,3,4,5,…}

A

yes

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16
Q

is a set or not?

x = {1,2,3,…, 35, 37}

A

yes

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17
Q

equal or not

{u,g,h} = {h,u,g}

A

equal

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18
Q

equal or not
{h,g, u,h} = {h, g, u}

A

not

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19
Q

are repeated occurences allowed in sets

A

no

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20
Q

What are natural numbers?

A

N={0,1,2,3,4,5,…}

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21
Q

What are integers?

A

Z = {…,-2,-1,0,1,2,…}

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22
Q

What are rational numbers?

A

Q={…, -1/2, 0, .08,…}

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23
Q

What are real numbers?

A

R={…,-2, -1/2, 0, .08, 3, √3, π(22/7),…}

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24
Q

If A ⊆ B and there is some element in B that does not occur in A,

A

proper subset

A ⊂ B

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25
The collection of all subsets of a set is called the
power set
26
what is the powerset of S = {a, b, c}
S = {∅, {a}, {b}, {c}, {a,b}, {a,c},..., {a,b,c}}
27
consists of one or more closed curves in which the interior of each curve represents a set.
Venn Diagram
28
who created the Venn Diagram
John Venn
29
___________ of two sets A and B is the set of all elements that are either in A or in B or in both A and B
union A U B
30
The _________ of two sets A and B is the set of all elements that are in both A and B
intersection A ∩ B
31
If A ∩ B = ∅, then A and B are said to be
disjoint
32
is the set of elements in A that are not in B
Difference (relative complement) A-B
33
is the set of elements in A that are not in B, and in B but not in A
symmetric difference
34
the difference U − A is called the
complement A'
35
The size of a set S is called its
cardinality
36
) is a collection of objects that may contain repeated occurrences of elements
bag (or multiset
37
T or F there is order and arrangement in bags or multisets
F
38
equal or not? Bag ed. [h,u,g,h] = [h,u,g]
NOT
39
is the first one a subbag of the second? [a, b,a] ⊆ [a, b]
NOPE
40
T OR F | There is no order in sets
T
41
What is the Inclusion-Exclusion principle
|A ∪ B| = |A| + |B| − |A ∩ B|
42
is a collection of things, called its elements, where there is a first element, a second element, and so on.
Tuple
43
What are the things inside tuples called?
members
44
The 0-tuple is denoted by ___________
( ), and we call it the empty tuple
45
2-tuple is often called an
ordered pair
46
equal or not. (3,7) = (7,3)
NOT IT IS TUPLE STUPIT
47
Characteristic of tuple?
Yes repeat is good YES ARRANGEMENT MATTERS
48
is denoted by A × B, is the set of all ordered pairs (a, b)
Cartesian product
49
can be thought of as a table of objects that are indexed by rows and columns
Matrix
50
finite ordered sequence of zero or more elements that can be repeated.
List
51
what’s the difference between tuples and lists?
tuples, we can randomly access any component in a constant amount of time. lists, we can randomly access only two things in a constant amount of time. (Heads and tails)
52
number of elements in a list is called its
length
53
Whyat is the heads and tails of
heads = tails =
54
will be used to denote this construction operation
cons
55
A = B = What is cons(head(A), head(B)) ?
56
A = B = What is cons(A, B) ?
< ,N, r,t,y,j>
57
he block of memory contains the element together with an address
(called a pointer or link
58
is a finite ordered sequence of zero or more elements that are placed next to each other in juxtaposition
string
59
make up a string are taken from a finite set called
Alphabet
60
string over of {a,b,c}
a, bc, abba, bbcba
61
string with no element is called the
empty string
62
is a set of strings
language
63
is a written number.
numeral
64
represent the set of positive integers by using the alphabe
Roman numerals
65
set of natural numbers using the alphabet
decimal numerals
66
represent the natural numbers using the alphabet
Binary numbers
67
We can combine two languages L and M to obtain the set of all concatenations of strings in L with strings in M
Product of languages
68
L = {ab, ac} M = {a, bc, abc} LM = ?
{aba, abbc, ababc, aca, acbc, acabc}
69
is a set of n-tuples, where the elements in each tuple are related in some way.
Relation
70
Another term for 1-ary, 2-ary, and 3-ary,
unary, binary, and ternary
71
is a collection of facts that are represented by tuples such that the tuples can be accessed in various ways to answer queries about the facts.
relational database
72
What is product rle?
|A × B| = |A||B|
73
informal proof is a demonstration that some statement is true
informal proof
74