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7.5.10.0. makeUf4
Procedure from library ncalg.lib (see ncalg_lib).
- Usage:
- makeUf4([p]); p an optional integer (field characteristic)
- Return:
- a ring, describing U(f_4)
- Note:
- You have to activate this ring with the 'setring' command. The presentation of U(f_4) is derived from the Chevalley representation of f_4, positive resp. negative roots are denoted by x(i) resp. y(i); Cartan elements are denoted by h(i).
Example:
| | LIB "ncalg.lib";
def ncAlgebra = makeUf4();
ncAlgebra;
==> // coefficients: QQ
==> // number of vars : 52
==> // block 1 : ordering dp
==> // : names X(1) X(2) X(3) X(4) X(5) X(6) X(7) X(8) X(\
9) X(10) X(11) X(12) X(13) X(14) X(15) X(16) X(17) X(18) X(19) X(20) X(21\
) X(22) X(23) X(24) Y(1) Y(2) Y(3) Y(4) Y(5) Y(6) Y(7) Y(8) Y(9) Y(10) Y(\
11) Y(12) Y(13) Y(14) Y(15) Y(16) Y(17) Y(18) Y(19) Y(20) Y(21) Y(22) Y(2\
3) Y(24) H(1) H(2) H(3) H(4)
==> // block 2 : ordering C
==> // noncommutative relations: ...
setring ncAlgebra;
// ... 552 noncommutative relations
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See also:
makeUe6;
makeUe7;
makeUe8;
makeUg2;
makeUsl;
makeUso5;
makeUsp1.
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