Notes for AKT-091008-2/0:15:17

Weight systems without a representation:

Tensor algebra (of lie algebra ${\mathcal {G}}$): $T({\mathcal {G}})=\{$ words with letters in ${\mathcal {G}}\}/$linearity in the letters

Universal enveloping algebra (of ${\mathcal {G}}$): $U({\mathcal {G}})=T({\mathcal {G}})/<[x,y]=xy-yx>$