In MarkDown editor played superscript and subscript and Greek letters

MarkDown editor played superscript and subscript and Greek letters

In markdown editor, how to achieve the underlying mathematical expression of it down there?
For example: [alpha] _{. 1} X _{. 1} + [alpha] ₂ X ₂ ² + [alpha] _{. 3} X _{. 3} ^{. 3}
Note: Greek alphabet used are given below

1. The three methods to achieve the subscript and superscripts

• A method (symbol)

	下标 ：α~1~ 
	上标 ：x^2^
	注意：输入法是英文输入法

• The results are as follows:
  index: [alpha] _{. 1}
  superscript: X ²

• Method 2 (HTML tags):

	下标 ：α<sub>1</sub>
	上标 ：x<sup>2</sup>

• The results are as follows:

  Index: [alpha] _{. 1}
  superscript: X ²

• Method 3 (Formula block):

	$$
	下标 ：α_1 ，上标 ：x^2
	$$

• The results are as follows:
  $Subscripts: α_1, superscript: x ^ 2$

2. Examples of the expression in writing:

α~1~x~1~+α~2~x~2~^2^+α~3~x~3~^3^

• Results: [alpha] _{. 1} X _{. 1} + [alpha] ₂ X ₂ ² + [alpha] _{. 3} X _{. 3} ^{. 3}

Common Greek alphabet

Α α：阿尔法 Alpha
Β β：贝塔 Beta
Γ γ：伽玛 Gamma
Δ δ：德尔塔 Delte
Ε ε：艾普西龙 Epsilon
Ζ ζ ：捷塔 Zeta
Ε η：依塔 Eta
Θ θ：西塔 Theta
Ι ι：艾欧塔 Iota
Κ κ：喀帕 Kappa
∧ λ：拉姆达 Lambda
Μ μ：缪 Mu
Ν ν：拗 Nu
Ξ ξ：克西 Xi
Ο ο：欧麦克轮 Omicron
∏ π：派 Pi
Ρ ρ：柔 Rho
∑ σ：西格玛 Sigma
Τ τ：套 Tau
Υ υ：宇普西龙 Upsilon
Φ φ：fai Phi
Χ χ：器 Chi
Ψ ψ：普赛 Psi
Ω ω：欧米伽 Omega

Editor's blog Markdown
Markdown common symbols and typographic