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Youwen Wu 2025-01-06 17:45:05 -08:00
parent 91cac8ff96
commit 560e8fdcb9
Signed by: youwen5
GPG key ID: 865658ED1FE61EC3
2 changed files with 65 additions and 30 deletions

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@ -1,5 +1,5 @@
#import "@preview/ctheorems:1.1.2": * #import "@preview/ctheorems:1.1.3": *
#import "@preview/showybox:2.0.1": showybox #import "@preview/showybox:2.0.3": showybox
#let colors = ( #let colors = (
rgb("#9E9E9E"), rgb("#9E9E9E"),
@ -257,27 +257,33 @@
shadow: (offset: (x: 2pt, y: 2pt), color: luma(70%)), shadow: (offset: (x: 2pt, y: 2pt), color: luma(70%)),
) )
#let problem = problem-style("problem", "Problem") #let exercise = problem-style("item", "Exercise")
#let problem = exercise
#let theorem-style = builder-thmbox( #let theorem-style = builder-thmbox(
color: colors.at(6), color: colors.at(6),
shadow: (offset: (x: 3pt, y: 3pt), color: luma(70%)), shadow: (offset: (x: 3pt, y: 3pt), color: luma(70%)),
) )
#let theorem = theorem-style("theorem", "Theorem") #let example-style = builder-thmbox(
#let lemma = theorem-style("lemma", "Lemma") color: colors.at(16),
#let corollary = theorem-style("corollary", "Corollary") shadow: (offset: (x: 3pt, y: 3pt), color: luma(70%)),
)
#let theorem = theorem-style("item", "Theorem")
#let lemma = theorem-style("item", "Lemma")
#let corollary = theorem-style("item", "Corollary")
#let definition-style = builder-thmline(color: colors.at(8)) #let definition-style = builder-thmline(color: colors.at(8))
#let definition = definition-style("definition", "Definition") // #let definition = definition-style("definition", "Definition")
#let proposition = definition-style("proposition", "Proposition") #let proposition = definition-style("item", "Proposition")
#let remark = definition-style("remark", "Remark") #let remark = definition-style("item", "Remark")
#let observation = definition-style("observation", "Observation") #let observation = definition-style("item", "Observation")
#let example-style = builder-thmline(color: colors.at(16)) // #let example-style = builder-thmline(color: colors.at(16))
#let example = example-style("example", "Example").with(numbering: none) #let example = example-style("item", "Example").with(numbering: none)
#let proof(body, name: none) = { #let proof(body, name: none) = {
thmtitle[Proof] thmtitle[Proof]
@ -289,3 +295,26 @@
h(1fr) h(1fr)
$square$ $square$
} }
#let fact = thmplain(
"item",
"Fact",
titlefmt: strong,
separator: ".",
inset: 0pt,
)
#let abuse = thmplain(
"item",
"Abuse of Notation",
titlefmt: strong,
separator: ".",
inset: 0pt,
)
#let definition = thmplain(
"item",
"Definition",
titlefmt: strong,
separator: ".",
inset: 0pt,
)

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@ -1,8 +1,11 @@
#import "./dvd.typ": * #import "./dvd.typ": *
#import "@preview/ctheorems:1.1.3": *
#show: dvdtyp.with( #show: dvdtyp.with(
title: "Probability and Statistics", title: "PSTAT120A Course Notes",
author: "Youwen Wu", author: "Youwen Wu",
date: "Winter 2024",
subtitle: "Taught by Brian Wainwright",
) )
#outline() #outline()
@ -11,9 +14,9 @@
== Preliminaries == Preliminaries
#definition("Statistics")[ #definition[
The science dealing with the collection, summarization, analysis, and Statistics is the science dealing with the collection, summarization,
interpretation of data. analysis, and interpretation of data.
] ]
== Set theory for dummies == Set theory for dummies
@ -21,8 +24,8 @@
A terse introduction to elementary set theory and the basic operations upon A terse introduction to elementary set theory and the basic operations upon
them. them.
#definition[Set][ #definition[
A collection of elements. A Set is a collection of elements.
] ]
#example[Examples of sets][ #example[Examples of sets][
@ -42,12 +45,12 @@ $ {"expression with" x | "conditions on" x} $
We also have notation for working with sets: We also have notation for working with sets:
With arbitrary sets $A$, $B$, $Omega$: With arbitrary sets $A$, $B$:
+ $a in A$ ($a$ is a member of the set $A$) + $a in A$ ($a$ is a member of the set $A$)
+ $a in.not A$ ($a$ is not a member of the set $A$) + $a in.not A$ ($a$ is not a member of the set $A$)
+ $A subset.eq Omega$ (Set theory: $A$ is a subset of $Omega$) (Stats: $A$ is a sample space in $Omega$) + $A subset.eq B$ (Set theory: $A$ is a subset of $B$) (Stats: $A$ is a sample space in $B$)
+ $A subset Omega$ (Proper subset: $A != Omega$) + $A subset B$ (Proper subset: $A != B$)
+ $A^c$ or $A'$ (read "complement of $A$") + $A^c$ or $A'$ (read "complement of $A$")
+ $A union B$ (Union of $A$ and $B$. Gives a set with both the elements of $A$ and $B$) + $A union B$ (Union of $A$ and $B$. Gives a set with both the elements of $A$ and $B$)
+ $A sect B$ (Intersection of $A$ and $B$. Gives a set consisting of the elements in *both* $A$ and $B$) + $A sect B$ (Intersection of $A$ and $B$. Gives a set consisting of the elements in *both* $A$ and $B$)
@ -56,13 +59,14 @@ With arbitrary sets $A$, $B$, $Omega$:
We can also write a few of these operations precisely as set comprehensions. We can also write a few of these operations precisely as set comprehensions.
+ $A subset Omega => A = {a | a in Omega, forall a in A}$ + $A subset B => A = {a | a in B, forall a in A}$
+ $A union B = {x | x in A or x in B}$ (here $or$ is the logical OR) + $A union B = {x | x in A or x in B}$ (here $or$ is the logical OR)
+ $A sect B = {x | x in A and x in B}$ (here $and$ is the logical AND) + $A sect B = {x | x in A and x in B}$ (here $and$ is the logical AND)
+ $A \\ B = {a | a in A and a in.not B}$ + $A \\ B = {a | a in A and a in.not B}$
+ $A times B = {(a,b) | forall a in A, forall b in B}$ + $A times B = {(a,b) | forall a in A, forall b in B}$
Convince yourself that these definitions are equivalent to the previous ones. Take a moment and convince yourself that these definitions are equivalent to
the previous ones.
#example[The real plane][ #example[The real plane][
The real plane $RR^2$ can be defined as a Cartesian product of $RR$ with itself. The real plane $RR^2$ can be defined as a Cartesian product of $RR$ with itself.
@ -70,14 +74,15 @@ Convince yourself that these definitions are equivalent to the previous ones.
$ RR^2 = RR times RR $ $ RR^2 = RR times RR $
] ]
Check your intuition that this makes sense. Why do you think $RR^n$ was chosen as the notation for $n$ dimensional spaces in $RR$? Check your intuition that this makes sense. Why do you think $RR^n$ was chosen
as the notation for $n$ dimensional spaces in $RR$?
#remark[Disjoint sets][ #remark[Disjoint sets][
If $A sect B$ = $emptyset$, then we say that $A$ and $B$ are *disjoint*. If $A sect B$ = $emptyset$, then we say that $A$ and $B$ are *disjoint*.
] ]
#theorem[Properties of set operations][ #fact[Properties of set operations][
+ DeMorgan's Laws: For any sets $A$ and $B$, we have DeMorgan's Laws:
+ $(A union B)' = A' sect B'$ + $(A union B)' = A' sect B'$
+ $(A sect B)' = A' union B'$ + $(A sect B)' = A' union B'$
] ]
@ -87,9 +92,9 @@ Check your intuition that this makes sense. Why do you think $RR^n$ was chosen a
+ $(sect_i A_i)' = union_i A_i'$ + $(sect_i A_i)' = union_i A_i'$
] ]
=== Sizes of infinity == Sizes of infinity
#definition("Cardinality")[ #definition[
Let $N(A)$ be the number of elements in $A$. $N(A)$ is called the _cardinality_ of $A$. Let $N(A)$ be the number of elements in $A$. $N(A)$ is called the _cardinality_ of $A$.
] ]
@ -119,3 +124,4 @@ When a set is uncountably infinite, its cardinality is greater than $aleph_0$.
] ]