extAlgRing -- the ring representation of the Ext-algebra

Synopsis

Usage:
R=L.cache.extAlgRing
Outputs:
- R, a polynomial ring

Description

If minmodelLie or extAlgLie of a Lie algebra L is computed up to a certain degree, then the ring representation of Ext_UL(k,k), where k is L.field may be obtained as L.cache.extAlgRing.

i1 : L=lieAlgebra({a,b},{{{1,-1},{[a,a,b],[b,b,a]}}})

o1 = L

o1 : LieAlgebra

i2 : minmodelLie 3

o2 = LieAlgebra{...12...}

o2 : LieAlgebra

i3 : L.cache.extAlgRing

o3 = QQ[ext , ext , ext ]
           0     1     2

o3 : PolynomialRing

extAlgRing -- the ring representation of the Ext-algebra

Synopsis

Description

See also

For the programmer