> [!tldr] Math of [[Mathematical Sets]] and [[Graph Theory]]
Discrete mathematics is the mathematics of sets, subsets, functions, and [[Graph]]s. It's also a class I never had a to take, which is a bummer because it introduces a set of mathematical symbols that always looked intimidating.
![[IMG_1745.jpeg|344]]
Discrete math also covers [[Ontology Relationship Characteristics]] - in short:
- **Reflexive** - an element links to itself
- **Symmetric** - elements link to each other
- **Transitive** - if A links to B and B links to C, then A links to C
- **Functional** - only *one* value for a given domain
![[Discrete Mathematics 2026-09-14 08.05.57.excalidraw.svg]]
%%[[Discrete Mathematics 2026-09-14 08.05.57.excalidraw.md|🖋 Edit in Excalidraw]]%%
## Copy/Pastable Discrete Math Symbols
### Logic Symbols
∧ - Logical AND (conjunction)
∨ - Logical OR (disjunction)
¬ - Logical NOT (negation)
→ - Conditional (implication)
↔ - Biconditional (if and only if)
∀ - Universal quantifier (for all)
∃ - Existential quantifier (there exists)
### Set Theory Symbols
∈ - Element of
∉ - Not an element of
∅ - Empty set
⊆ - Subset of
∪ - Set union
∩ - Set intersection
∖ - Set difference
### Number Systems
ℕ - Natural numbers
ℤ - Integers
ℚ - Rational numbers
ℝ - Real numbers
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# More
## Source
- [[The Engineered Design of Systems]]
- The copy/paste section is straight from Google AI