Sets & Notation: Homework Explained

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SUMMARY

The discussion clarifies the notation and meaning of functions and set relationships in set theory. Specifically, T: R x R -> R indicates that the function T maps pairs of elements from set R to a single element in R, exemplified by T(x,y) = x + y for real numbers. Additionally, the notation A ⊆ B signifies that all elements of set A are contained within set B, but does not imply that A and B are identical; A ⊂ B indicates that A is a proper subset of B, meaning B contains elements not found in A.

PREREQUISITES
  • Understanding of set theory concepts, including sets and subsets.
  • Familiarity with Cartesian products in mathematics.
  • Basic knowledge of functions and their notation.
  • Comprehension of mathematical symbols and their meanings.
NEXT STEPS
  • Study the properties of Cartesian products in set theory.
  • Learn about different types of functions and their representations.
  • Explore the distinctions between subsets, proper subsets, and equality of sets.
  • Investigate real-world applications of set theory in computer science and mathematics.
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Students of mathematics, educators teaching set theory, and anyone seeking to deepen their understanding of functions and set relationships.

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Homework Statement


Hi all.

If I have a set R and a function T, then what does the following mean: T: R x R -> R?

Also, when I have a set A and a set B, then does the following mean that all elements in A are equal to all elements in B? A [itex]\subseteq[/itex] B
 
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Niles said:

Homework Statement


Hi all.

If I have a set R and a function T, then what does the following mean: T: R x R -> R?
RxR, the Cartesian product, is the set of all pairs, (x,y), where each of x and y is in R. T: R x R->R means that T is a function that, to every such pair, (x,y), assigns a member of R.

Operations are often represented that way. For example, if R is the set of real numbers, R x R is the set of pairs of real numbers and addition, "+", assigns a single number to every pair of numbers: T(x,y)= x+ y so T: R x R-> R.

Also, when I have a set A and a set B, then does the following mean that all elements in A are equal to all elements in B? A [itex]\subseteq[/itex] B
No, not if by "all elements in A are equal to all elements in B" you mean they are the same set. [itex]A \subset A[/itex] means that all elements of A are in B, but there are some elements of B that are not in A. [itex]A\subseteq B[/itex] includes the possibility that there are no elements of B that are not in A- the possiblility that A= B.
 
Thank you. Two very good answers for two questions.

That cleared things up.
 

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