Wolfram Language & System 11.0 (2016)|Legacy Documentation

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lhs!=rhs or lhsrhs
returns False if lhs and rhs are identical.


  • can be entered as x[NotEqual]y or x Esc!=Esc y.
  • lhsrhs returns True if lhs and rhs are determined to be unequal by comparisons between numbers or other raw data, such as strings.
  • Approximate numbers are considered unequal if they differ beyond their last two decimal digits.
  • gives True only if none of the ei are equal. 232->False.
  • lhsrhs represents a symbolic condition that can be generated and manipulated by functions like Reduce and LogicalExpand.
  • Unequal[e] gives True.
  • For exact numeric quantities, Unequal internally uses numerical approximations to establish inequality. This process can be affected by the setting of the global variable $MaxExtraPrecision.
  • In StandardForm, Unequal is printed using .

ExamplesExamplesopen allclose all

Basic Examples  (2)Basic Examples  (2)

Returns True if elements are guaranteed unequal, and otherwise stays unevaluated:

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Enter as != or as Esc!=Esc:

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Introduced in 1988
| Updated in 1996