MathDB
Problems
Contests
Undergraduate contests
Putnam
1962 Putnam
B2
Putnam 1962 B2
Putnam 1962 B2
Source: Putnam 1962
May 21, 2022
Putnam
function
Uncountable set
Problem Statement
Let
S
S
S
be the set of all subsets of the positive integers. Construct a function
f
:
R
→
S
f \colon \mathbb{R} \rightarrow S
f
:
R
→
S
such that
f
(
a
)
f(a)
f
(
a
)
is a proper subset of
f
(
b
)
f(b)
f
(
b
)
whenever
a
<
b
.
a <b.
a
<
b
.
Back to Problems
View on AoPS