Important Symbols
⇒ rArr
∪ cups
∩ caps
∈ isinv
∉ notinva
⊂ subset
⊆ subseteqq
⊈ nusbseteqq
⊃ supset
⊇ supseteqq
⊉ nsupseteqq
← slarr
↑ uparrow
→ srarr
↓ downarrow
↦ mapsto
□ square
∃ exist
∄ nexists
ℕ naturals
ℙ primes
ℚ rationals
ℝ reals
ℤ integers
∅ varnothing