grouping (parentheses)

Equations (=), inequalities, and inequations (not =) as expressions (e.g. x = x, treated as an expression, reduces to true)

power towers, finite and infinite

nested radicals, finite and infinite

hyperoperations

multivariable and vector calculus

integral transforms and other transforms

operators (differential and integral, vector)

probability and statistics operators

sets and set operations (union, intersection, ...)

logic (and, or, not, implication, truth values, quantifiers, higher order logic...)

vectors and matrices and their operations

roots of polynomials that cannot be expressed as radicals (e.g. roots of x^5 + x + 1)

complex numbers and other categories of numbers (natural, integer, rational, real, quaternions, ...)

combinatorics (combinations, permutations, ...)

functions as expressions (e.g. f(x + a) + b as an expression)

and many more...

75.46.182.198 (talk) 02:05, 6 June 2018 (UTC)