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 GenRepr

representation in terms of generators
 Syntax
 ``` GenRepr(X:POLY, I:IDEAL):LIST of POLY GenRepr(X:VECTOR, I:MODULE):LIST of POLY ```

 Description
This function returns a list giving a representation of X in terms of generators for I. Let the generators for I be [G_1,...,G_t]. If X is in I, then GenRepr will return a list [F_1,...,F_t] such that
```             X = F_1*G_1 + ... + F_t*G_t.
```
If X is not in I, then GenRepr returns the empty list, [].

 Example
 ``` Use R ::= QQ[x,y]; I := Ideal(x+y^2,x^2-xy); GenRepr(x^3-x^2y-y^3-xy, I); [-y, x] ------------------------------- -y I.Gens[1] + x I.Gens[2]; x^3 - x^2y - y^3 - xy ------------------------------- GenRepr(x+y, I); [ ] ------------------------------- x+y IsIn I; -- the empty list was returned above since x+y is not in I FALSE ------------------------------- V1:= Vector(x,y,y^2); V2:= Vector(x-y,0,x^2); X := x^2 V1 - y^2 V2; M := Module(V1, V2); GenRepr(X, M); [x^2, -y^2] ------------------------------- ```