ComplexityFunction is an option for Simplify and other functions which gives a function to rank the complexity of different forms of an expression.

IntegerQ[expr] gives True if expr is an integer, and False otherwise.

Mathematica handles both integers and real numbers with any number of digits, automatically tagging numerical precision when appropriate. Mathematica internally uses several ...

DeleteCases[expr, pattern] removes all elements of expr that match pattern. DeleteCases[expr, pattern, levelspec] removes all parts of expr on levels specified by levelspec ...

InexactNumberQ[expr] returns True if expr is an inexact real or complex number, and returns False otherwise.

AllowReverseGroupClose is an option for Cell that specifies whether a cell group can be reverse closed.

The notion of expressions is a crucial unifying principle in Mathematica. It is the fact that every object in Mathematica has the same underlying structure that makes it ...

At the core of Mathematica is the foundational idea that everything —data, programs, formulas, graphics, documents—can be represented as symbolic expressions. And it is this ...

Through[p[f_1, f_2][x]] gives p[f_1[x], f_2[x]]. Through[expr, h] performs the transformation wherever h occurs in the head of expr.

_or Blank[] is a pattern object that can stand for any Mathematica expression. _h or Blank[h] can stand for any expression with head h.