- ExtElement -- unary negation

• 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 $x$

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