Discrete Mathematics: Basic Proof Techniques and Terminologies

Why Study Proof Techniques?

  • Improving Analytical Skills: The study of proofs is essential for developing the ability to examine complex structures and identify the logical connections between different elements.
  • Improving Problem-Solving Skills: Proof techniques provide a structured methodology for approaching problems, allowing for a systematic breakdown of a problem into solvable components based on logical rigor.
  • Understanding Concepts: Proofs are fundamental to a deep comprehension of mathematical concepts; they go beyond the Surface-level "how" to explain the "why" behind mathematical truths.

Basic Terminologies in Discrete Mathematics

  • Discrete mathematics relies on a specific set of foundational terminologies to build logical systems. These include definitions, theorems, and axioms.

Definitions

  • Fundamental Nature: A definition is something that is given and accepted without the requirement of a proof.
  • Function: Definitions are primarily used to create and introduce new concepts by defining them in terms of previously existing and understood concepts.
  • Named Example (Even Integers): An integer nn is defined as being an even number if and only if there exists another integer kk such that the following relationship is true:

n=2kn = 2k

Theorems

  • Core Requirement: A theorem is described as something that requires a proof to be established as true.
  • Status: Formally, a theorem is a proposition that has been successfully proved to be true through logical deduction.

Axioms

  • Unprovable Rules: Axioms represent the most basic level of truth in a system. They are unprovable rules that are used as the starting point for further reasoning.
  • Constant Truth: An axiom is a statement that is accepted as being always true without the need for a demonstration.
  • Specific Example (Geometry): A classic example of an axiom is the statement that given two distinct points, there is exactly one line that contains them.
  • Self-Referential Principle: It is noted that the statement "axioms are true" is itself considered an axiom within mathematical philosophy.