Key to ASCII notation

• '{}' = ∅ = "empty set"
• '(-' = ∈ = "element of"
• '(_' = ⊆ = "subset of" (not strict)
• 'u' = ∪ = "union"
• 'n' = ∩ = "intersection"
• '~L' = L = "complement of L"
• '-]' = ∃ = "there exists"
• '\-/' = ∀ = "for all"
• '/\' = ∧ = "and"
• '\/' = ∨ = "or"
• '->' = → = "implies"
• '<->' = ↔ = "if and only if (iff)"
• '!' = ¬ = "not", e.g., 'a != b' = a ≠ b = "a is not equal to b", 'w !(- L' = w ∉ L = "w is not an element of L", etc.
• '\sum' = ∑ = summation sign
• '\prod' = ∏ = product sign
• '\Sigma' = Σ = capital greek letter Sigma, '\delta' = δ = lowercase greek letter delta, etc.
• '|_x_|' = ⌊x⌋ = floor(x)
• '|^x^|' = ⌈x⌉ = ceiling(x)
• '_' indicates a subscript, e.g., 'q_1' = q₁
• '^' indicates a superscript, e.g., 'n^2' = n²
• curly braces '{}' surround longer subscripts/superscripts, e.g., '\sum_{0 <= i <= n} 2^{i/2}' = ∑_{0 ≤ i ≤ n} 2^i/2