Typing between the codes you can 
          format        your            post!

Using these html codes you can also get: 
Superscripts:                  A[sup]n[/sup] gives An
Subscripts:                    A[sub]n[/sub] gives An
Degree sign:                   ° gives °
Plus-minus                     ± gives ±
Multiplication sign            × gives ×
Imaginary                      ℑ gives ℑ
Real                           ℜ gives ℜ
Left arrow                     ← gives ←
Up arrow                       ↑ gives ↑
Right arrow                    → gives →
Down arrow                     ↓ gives ↓
Left/right arrow               ↔ gives ↔
For All                        ∀ gives ∀
Partial differential           ∂ gives ∂ 
There exists                   ∃ gives ∃
Empty set                      ∅ gives ∅
Nabla                          ∇ gives ∇
Element of                     ∈ gives ∈
Not Element of                 ∉ gives ∉
Product sign                   ∏ gives ∏
SUM sign                       ∑ gives ∑
Minus sign                     − gives −
Radical sign                   √ gives √
Infinity                       ∞ gives ∞
Angle                          ∠ gives ∠
AND                            ∧ gives ∧
OR                             ∨ gives ∨
Intersection                   ∩ gives ∩
Union                          ∪ gives ∪
Integral                       ∫ gives ∫
Not equal                      ≠ gives ≠
Equivalent                     ≡ gives ≡
Less than or equal             ≤ gives ≤
Greater than or equal          ≥ gives ≥
Subset                         ⊆ gives ⊆
NOT a Subset                   ⊄ gives ⊄