Talk:Mathematical notation/to do

• Give proper definition. ---> added a first cut at it.
• some of this properly belongs in History of mathematics, but
  • The first use of a symbol for free variables (Egyptian heap)
  • Diophantine equations
  • Ratios and proportions
  • symbols for Integrals and sums -- when they first arose
  • Hindu-Arabic notation for numbers
  • Knuth arrow notation - Graham's number
  • O notation