Exercices 4b

1. A relation is defined as a binary predicate. For instance, if there is a link between A and B, we can write:

link A B
link A C

2. How to define that there is a path between X and Y if there is a link between X and Y ?
3. How to define that the path relationship is symétric ? And transitive ?
4. How to prove that there is a path between C and B ?

answer

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