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Transitieve Relatie

Als A > B en B > C, dan A > C. Geldt voor ordeningsrelaties.

Leren

Als A > B en B > C, dan A > C. Geldt voor ordeningsrelaties.

A transitive relation is one where if the relation holds between A and B, and between B and C, then it must hold between A and C. Common transitive relations include 'greater than', 'less than', 'older than', 'taller than', 'ancestor of', and 'implies'. Recognizing transitivity allows us to chain comparisons and orderings together.

R(a,b) ∧ R(b,c) → R(a,c)

  • Alice is taller than Bob. Bob is taller than Carol. Therefore, Alice is taller than Carol.
  • 5 > 3 and 3 > 1, therefore 5 > 1.
  • New York is larger than Chicago. Chicago is larger than Houston. Therefore, New York is larger than Houston.
  • Iron is heavier than aluminum. Aluminum is heavier than plastic. Therefore, iron is heavier than plastic.

Zo herkent u het

  • Look for comparative statements using the same relation (taller than, faster than, older than, etc.)
  • Check if there's a 'middle' element that appears in both comparisons
  • The conclusion compares the 'outer' elements using the same relation

Veelgemaakte fouten

  • Not all relations are transitive. 'Is a friend of' is NOT transitive (A's friend's friend may not be A's friend)
  • 'Is next to' is NOT transitive (if A is next to B, and B is next to C, A may not be next to C)
  • Applying transitivity to non-transitive relations leads to invalid conclusions

Stapsgewijze uitwerking

Alice is langer dan Bob. Bob is langer dan Carol. Wie is het langst?

  1. Identificeer de eerste vergelijking: Alice > Bob (lengte)
  2. Identificeer de tweede vergelijking: Bob > Carol (lengte)
  3. Vind het gemeenschappelijke element: Bob verschijnt in beide
  4. Pas transitiviteit toe: Alice > Bob > Carol, dus Alice > Carol

Antwoord: Alice is tallest

Oefenadvies

Logische Deductie

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