# - ExtElement -- unary negation

## Synopsis

• Operator: -
• Usage:
u = - x
• Inputs:
• x, an instance of the type ExtElement, $x$ is of type $E$, where $E$ is of type ExtAlgebra
• Outputs:
• u, an instance of the type ExtElement, $u$ is of type $E$, the negation of $x$

## Description

The symbol - is used as notation for the Ext-algebra negation.

 i1 : L = lieAlgebra{a,b,c}/{a b,b c} o1 = L o1 : LieAlgebra i2 : E = extAlgebra(3,L) o2 = E o2 : ExtAlgebra i3 : -(2 ext_3-ext_4) o3 = - 2ext_3 + ext_4 o3 : E