was@form:~$ magma
Magma V2.11-1     Sat Aug  7 2004 19:04:27 on form     [Seed = 1981966581]
Type ? for help.  Type <Ctrl>-D to quit.

Loading startup file "/home/was/magma/local/init.m"

> M := MS(141,2,+1);
> D := ND(CS(M));
> D;
[
Modular symbols space for Gamma_0(141) of weight 2 and dimension 1 over Rational Field,
Modular symbols space for Gamma_0(141) of weight 2 and dimension 1 over Rational Field,
Modular symbols space for Gamma_0(141) of weight 2 and dimension 1 over Rational Field,
Modular symbols space for Gamma_0(141) of weight 2 and dimension 1 over Rational Field,
Modular symbols space for Gamma_0(141) of weight 2 and dimension 1 over Rational Field,
Modular symbols space for Gamma_0(141) of weight 2 and dimension 2 over Rational Field,
Modular symbols space for Gamma_0(141) of weight 2 and dimension 8 over Rational Field
]
> ModularDegree(D[1]);
2
> ModularDegree(D[2]);
12
> ModularDegree(D[3]);
6
> ModularDegree(D[r5]);

>> ModularDegree(D[r5]);
                   ^
User error: Identifier 'r5' has not been declared or assigned
> ModularDegree(D[4]);
6
> ModularDegree(D[5]);
14
> E := D[5];
> factor(141);
[ <3, 1>, <47, 1> ]
1
> M47 := ModularSymbols(47,2,+1);
> D47 := ND(CS(M47));
> D47;
[
Modular symbols space for Gamma_0(47) of weight 2 and dimension 4 over Rational Field
]
> IntersectionGroup(M!!D47[1],E);