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wellcome to this new lecture on sets
in this lecture we will learn new ways to describe sets
of course
we know how to describe sets using curly brackets or
by symbols like N, Z
Q or R
or we can expect satisfied works
but in this lecture you'll see some of you
weeks to describe sense
but let's first
but a look at an example
considered set
all
real acts
this zero misery for the next
accidents or equal benoit
if you look a little bit closer at this example n_b_c_
that we are using
and known set do we have to set up real numbers
and some statements about amendments
this set
of real numbers is quote the reference that
statements
uh... dark
what we call predicates
there's treatments
all the elements in
in the reference at the park
and statement
is arthur of such predicate
it's as if true
or falls
but never
so
what we have
cassette
reference that i_v_f_ statement about elements in this half
and such as
statement gets tighter true
that's a bit declarative statement
in general at predicate it's just a statement about
alamance but some set
and end its statement two very poor chris
and statement is that
true or falls for each valued at this valuable content
so let's have a look at some examples
of course the first example disease
seven pacific time
that state
and also
to pie
it's cirrhosis fraction the sign
which is also a statement
well statements can be true or false
for example
i have a brother
but this is
true
or it's false can never be cruel also the same time
and similar
yes statement that paris
is capital or france
it's true statement
but of course you also have a statement like angel domestic epochal off the
netherlands it's still a statement but that's not true
most of mark's office examples park real nice
x's positive
that's a statement about real number it's true
or falls
side affects its western cough
that can be true
falls
and can never be
true or false
uh... boats at the same time
exit zero off the coast site
which is also a nice day
in general
predicate
this reference that
also defines a set
and accept the denote bike curly bracket exp
capital acts
and uh... bar
denoting the statement p affects
so this set consists of all those x
the reference that
for which two statements p affects it's true
instead of using this bar sometimes people use
let's take a call in or are semicolon
to denote please
between you used it for tej
that name
of despair evil
in our example as pacs
outside the definition this accepts no meaning
so inside
this definition it s reference sample but outside
not any value so army say this experts valuable tax
responded state
that seven example
for example consider
the following sat
bt from are
and yet predicate x's
bigger dancing
this denotes the set of
all positive friel numbers
second example is a following
you take paul allen's except from
set set up and the jobs
best predicate said is that as well by two
discusses all
you can
integer
so dats zero
minus two minus twenty
plus forty
we have twelve c
something you waste
off describing except
using a predicate
predicate
*** statement
apart variables
dot com from reconcile debbie argues
it this weekend to strike a lot of sense
see you next lecture