- Pairs as Universal Glue
- n-dimensional points, lines, figures
- Data types and Data abstractions
- The basic question is "what can you do with it?"
- Conventions for Usage and Standardization
- Plugs and telephone connectors
- lists are a standard usage of pairs in
Scheme/Lisp (the rest of the world calls it "singly linked list")
- trees are a common use of pairs, but they aren't
standardized
