Created at 2023-01-12 # [Anonymous feedback](https://www.admonymous.co/louis030195) # [[Epistemic status]] #shower-thought Last modified date: 2023-01-12 Commit: 0 # Related - [[Mathematic/Algebra]] - [[Mathematic/Calculus/Lambda calculus]] - [[Mathematic/Mathematical structure]] - [[Mathematic/Symmetry]] # TODO > [!TODO] TODO # Principia mathematica symbols Principia Mathematica, written by Sir Isaac Newton in 1687, lays out the foundations of calculus and Newton's laws of motion. It is considered one of the most important works in the history of science. Principia Mathematica, written by Bertrand Russell and Alfred North Whitehead, is a three-volume work on the foundations of mathematics, published between 1910 and 1913. It is an attempt to derive all mathematical truths from a small set of logical axioms and rules of inference. It is considered a significant work in the field of mathematical logic and the philosophy of mathematics. In summary, the first Principia Mathematica is about physics, the second one is about mathematics and logic. | Symbol | Meaning | | ------- | -------------------------------- | | ⊃ | Implication | | ≡ | Equality | | ∧ | Conjunction | | ∨ | Disjunction | | → | Material implication | | ↔ | Material equivalence | | ∃ | Existential quantifier | | ∀ | Universal quantifier | | ∩ | Intersection of sets | | ∪ | Union of sets | | ⊆ | Subset of | | ⊇ | Superset of | | ∈ | Membership of a set | | ∉ | Non-membership of a set | | ∠ | Angle | | ≅ | Congruence | | ≈ | Approximate equality |