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Set Theory & Logic

Sets, relations, functions, cardinality, proof and the foundations of mathematics.

经验教训

Introductory Sets and operations Membership, subsets, union, intersection, complement, and Venn diagrams. {1,2,3,4} union {3,4,5,6} Core Relations, functions and equivalence Relations as sets of pairs; reflexive, symmetric, transitive; functions and bijections. truth table of p implies q Advanced Cardinality and infinity Countable and uncountable sets, Cantor's diagonal argument, the continuum. sum of 1/2^n for n = 0 to oo Core Logic and methods of proof Connectives, quantifiers, direct proof, contrapositive, contradiction, induction. truth table of (p implies q) iff (not p or q)

What mathematics is built on. Sets and the operations on them, relations and functions defined precisely, the sizes of infinity, and the logic that turns an argument into a proof.

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人们对人们提出的问题

Are some infinities bigger than others?

Yes. The integers and the rationals can be listed; the real numbers cannot (Cantor's diagonal argument), so there are strictly more reals than integers.

What is the difference between a relation and a function?

A relation pairs inputs with outputs freely; a function is a relation in which every input gets exactly one output.

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