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1. Mathematical symbols
The following mathematical symbols are all Greek letters with the following meanings:
- ∀: "Any"
- ∃: "existence"
- ∈: "belongs to"
- ∉: "Does not belong"
- א: Aleph, used to express the potential of the set (number of elements)
- δ, Δ: Delta, indicating the value of change
- E, ε: Epsilon, the base of the logarithm, E is used to represent the series sum in probability statistics
- ζ: cut tower, azimuth
- η: Aita, used as a general variable
- Θ θ ：Theta, generally means angle
- ∧ λ: Lambda, generally representing volume or variable
- ξ: Kersey
- Ω ω: Omega, generally means angle or variable
- Ψ ψ: Pusi, generally means angle or variable
- Φ φ: Buddha’s love, generally means angle or variable
- ∑ σ: Sigma, representing sum, σ is used to represent standard deviation in probability statistics
2. Commonly used Greek letters and their meanings in mathematics and physics
Three, potential
Real numbers are dense and ordered. Natural numbers and integers are discrete and ordered. The number of elements in the set corresponding to these different numbers is infinite, but the number of elements may be the same or different. The number of set elements The number is called potential.
- Potential: The number of set elements is called potential;
- Equipotential: The elements of the two sets A and B are equipotential. For example, natural numbers and integers are equipotential, because each integer i (including negative numbers) can use a natural number such as 2 abs(i) or 2 abs(i)-1 corresponds to (abs means absolute value), such as: 0 corresponds to 0, -1 corresponds to 1, 1 corresponds to 2,...
- Natural numbers, integers, rational numbers, etc., real numbers, real numbers squares, complex numbers, etc., but the latter’s potential is greater than the former, the former’s potential is ℵ₀ (Aleph 0), the latter is ℵ₁ (Aleff 1) ;
Note: Alev's number, also known as Alifu's number, is a series of ultra-poor base numbers in the branch of mathematics called set theory. Its symbol is ℵ (evolved from the Hebrew letter א ) plus a subscript indicating that the potential of a countable set (including natural numbers) is labeled ℵ₀, the next larger potential is ℵ₁, and the next one is ℵ2 ( Such as the number of unit continuous functions), and so on. Continue to continue, you can define a base for any ordinal α. ℵ₀<ℵ₁<ℵ2..., for learning AI, temporarily knowing the three numbers ℵ₀, ℵ₁, ℵ2 is enough
