Discrete Structures - Review Sheet | CS 173, Exams of Discrete Structures and Graph Theory

Material Type: Exam; Class: Discrete Structures; Subject: Computer Science; University: University of Illinois - Urbana-Champaign; Term: Unknown 1989;

Typology: Exams

Pre 2010

Uploaded on 03/16/2009

koofers-user-hsj-1
koofers-user-hsj-1 🇺🇸

8 documents

1 / 2

Toggle sidebar

This page cannot be seen from the preview

Don't miss anything!

bg1
p q T p q p q p p q q p q p q
T T T T T T T T T T
T F T T T T F F F F
F T T T F F T T F F
F F T F T F T F T F
p q p q p q¬q p !q¬p p "q p q F
T T F F F F F F F F
T F T T T T F F F F
F T T T F F T T F F
F F T F T F T F T F
Double Negation: ¬¬p p
pT pIdentity pF p
pF FDomination pT T
pp pIdempotence pp p
p¬p FNegation p¬p T
pq qpCommutativity pq qp
p(pq) pAbsorption p(pq) p
p(qr) (pq)rAssociativity p(qr) (pq)r
p(qr) (pq)(pr)Distribution p(qr) (pq)(pr)
¬(pq) ¬p¬qDe Morgan’s Laws ¬(pq) ¬p¬q
Simplification pq=p
Biconditional Elimination pq=pq
Addition p=pq
Trivial Proof q=pq
Vacuous Proof ¬p=pq
Modus Ponens p(pq) =q
Modus Tollens ¬q(pq) =¬p
Disjunctive Syllogism ¬p(pq) =q
Indirect Proof ¬q¬p=pq
Proof by Contradiction ¬pF=p
Reductio Ad Absurdum (pq)(p¬q) =¬p
Hypothetical Syllogism (pq)(qr) =pr
Separation of Cases (pq)(pr)(qr) =r
Biconditional Introduction (pq)(qp) =pq
Existential Instantiation xX:P(x) =Fix aXsuch that P(a)
Universal Instantiation aX xX:P(x) =P(a)
Existential Generalization aXP(a) = xX:P(x)
Universal Generalization P(a)for arbitrary aX= xX:P(x)
pf2

Partial preview of the text

Download Discrete Structures - Review Sheet | CS 173 and more Exams Discrete Structures and Graph Theory in PDF only on Docsity!

p q T p ∨ q p ← q p p → q q p ↔ q p ∧ q T T T T T T T T T T T F T T T T F F F F F T T T F F T T F F F F T F T F T F T F

p q p ↑ q p ⊕ q ¬q p! q ¬p p " q p ↓ q F T T F F F F F F F F T F T T T T F F F F F T T T F F T T F F F F T F T F T F T F

Double Negation: ¬¬p ⇐⇒ p p ∧ T ⇐⇒ p Identity p ∨ F ⇐⇒ p p ∧ F ⇐⇒ F Domination p ∨ T ⇐⇒ T p ∧ p ⇐⇒ p Idempotence p ∨ p ⇐⇒ p p ∧ ¬p ⇐⇒ F Negation p ∨ ¬p ⇐⇒ T p ∧ q ⇐⇒ q ∧ p Commutativity p ∨ q ⇐⇒ q ∨ p p ∧ (p ∨ q) ⇐⇒ p Absorption p ∨ (p ∧ q) ⇐⇒ p p ∧ (q ∧ r) ⇐⇒ (p ∧ q) ∧ r Associativity p ∨ (q ∨ r) ⇐⇒ (p ∨ q) ∨ r p ∧ (q ∨ r) ⇐⇒ (p ∧ q) ∨ (p ∧ r) Distribution p ∨ (q ∧ r) ⇐⇒ (p ∨ q) ∧ (p ∨ r) ¬(p ∧ q) ⇐⇒ ¬p ∨ ¬q De Morgan’s Laws ¬(p ∨ q) ⇐⇒ ¬p ∧ ¬q

Simplification p ∧ q =⇒ p Biconditional Elimination p ↔ q =⇒ p → q Addition p =⇒ p ∨ q Trivial Proof q =⇒ p → q Vacuous Proof ¬p =⇒ p → q Modus Ponens p ∧ (p → q) =⇒ q Modus Tollens ¬q ∧ (p → q) =⇒ ¬p Disjunctive Syllogism ¬p ∧ (p ∨ q) =⇒ q Indirect Proof ¬q → ¬p =⇒ p → q Proof by Contradiction ¬p → F =⇒ p Reductio Ad Absurdum (p → q) ∧ (p → ¬q) =⇒ ¬p Hypothetical Syllogism (p → q) ∧ (q → r) =⇒ p → r Separation of Cases (p ∨ q) ∧ (p → r) ∧ (q → r) =⇒ r Biconditional Introduction (p → q) ∧ (q → p) =⇒ p ↔ q

Existential Instantiation ∃x ∈ X : P (x) =⇒ Fix a ∈ X such that P (a) Universal Instantiation a ∈ X ∧ ∀x ∈ X : P (x) =⇒ P (a) Existential Generalization a ∈ X ∧ P (a) =⇒ ∃x ∈ X : P (x) Universal Generalization P (a) for arbitrary a ∈ X =⇒ ∀x ∈ X : P (x)

empty

set

{^

subset

A

B

∀a

:^

a^

∈^

A

a

B

proper

subset

A

B

A

B

B

A

set

equality

A

B

A

B

B

A

union

A

B

{a

|^

a^

A

a

B

intersection

A

B

{a

|^

a^

A

a

B

difference

A

^

B

{a

|^

a^

A

a

B

symmetric

difference

A

B

{a

|^

a^

A

a

B

complement

A

{a

|^

a^

A

}^

U

\

A

Cartesian

product

A

×

B

a,

b)

|^

a^

A

b

B

power

set

A 2

{B

|^

B

A

cardinality

|A

|^

of

elements

(if

finite)

Function

f

:^

A

B

f^

A

×

B

such

that

a^

A

:^

b^ ∈

B

:^

(a,

b)

f

function

notation

b^ =

f

(a

)^

a,

b)

f

image

f

(S

)^

{f

(a

)^ |

a

S

preimage

f

−^1

(b

)^

{a

|^

f^ (

a)

b

preimage

f

−^1

(T

)^

{a

|^

f^ (

a)

T

inverse

f

B

A

b,

a

)^ |

b

f

(a

(if

f

is

a

bijection)

composition

g

f

(g

f

a)

g

(f

(a

one-to-one,

injection

∀b

B

:^

|f

b)

|^ ≤

onto,

surjection

∀b

B

:^

|f

b)

|^ ≥

bijection

∀b

B

:^

|f

b)

|^ =

Binary

relation

A

×

A

relation

notation

a^

b

a,

b)

inverse

−^1

b,

a

)^ |

b

a

composition

a,

c)

|^

∃b

:^

a^

b

b

c

reflexive

∀a

A

:^

a^

a

symmetric

∀a,

b^

∈^

A

:^

a^

b

b

a

antisymmetric

∀a,

b^

∈^

A

:^

(a

b

b

a

)^ →

a

b

transitive

∀a,

b,

c^

∈^

A

:^

(a

b^

∧^

b^!

c

)^ →

a

c

Equivalence

relation

reflexive,

symmetric,

and

transitive

∃f

:^

A

B

:^

∀x,

y^

∈^

A

:^

x^

y

f

(x

)^ ∼

f

(y

equivalence

class

[x

]∼

{a

A

|^

x^

a

x^

y

[

x]

∼^

[y

]∼

x^

y

[

x]

∼^

[y

]∼

Partial

order

reflexive,

antisymmetric,

and

transitive

x^

and

y

are

comparable

x^

y

y

x

x^

and

y

are

incomparable

x^

y

y

x

total

order

∀x,

y^

∈^

A

:^

x^

y

y

x

x^

is

minimal

∀y

A

:^ y

x

x^

is

maximal

∀y

A

:^ x

y

x^

is

minimum

∀y

A

:^ x

y

x^

is

minimum

∀y

A

:^ y

x

Undirected

graph

G

V

,^ E

V^

,^

E

u,

v}

|^

u^

∈^

V^

v^

∈^

V^

u

v

subgraph

G

′^ =

(V

E

′)^

where

V

′^

V

and

E

′^ ⊆

E

walk

v^0

,^ v

v^2

,^.

.^.

,^ v

n^

where

vi

−^1

,^ v

}i

E

for

all

i

path

walk

with

no

repeated

vertices

cycle

walk

with

no

repeated

vertices

except

v

0

v

n

connected

walk

from

any

vertex

to

any

other

acyclic

no

subgraph

is

a

cycle

tree

connected

and

acyclic

E

|^ =

|V

|^ −

degree

sum

v∈

V^

deg

(v

)^ =

|E