ExtElement - ExtElement -- subtraction of Ext-algebra elements

Synopsis

• Operator: -

• Usage:

  u=x - y

• Inputs:
  • x, an instance of the type ExtElement, $x$ is of type $E$, where $E$ is of type ExtAlgebra
  • y, an instance of the type ExtElement, $y$ is of type $E$
• Outputs:
  • u, an instance of the type ExtElement, $u$ is of type $E$, the difference of $x$ and $y$

Description

i1 : L = lieAlgebra{a,b,c}/{a b,b c}

o1 = L

o1 : LieAlgebra

i2 : E = extAlgebra(3,L)

o2 = E

o2 : ExtAlgebra

i3 : basis(2,E)

o3 = {ext_3, ext_4}

o3 : List

i4 : ext_4-2 ext_3

o4 =  - 2ext_3 + ext_4

o4 : E

See also

• ExtAlgebra -- the class of all Ext-algebras