arl2 example is buggy

Bug Description

See https://help.scilab.org/arl2

Help file does not display a correct value.

Steps to reproduce

v = ones(1,20);
clf();
plot2d([], [v';zeros(80,1)], 2, '051',' ',[1,-0.5,100,1.5])

[d,n,e] = arl2(v, poly(1,'z','c'),1)
plot2d([], ldiv(n,d,100), 2, '000')
[d,n,e] = arl2(v,d,3)
plot2d([], ldiv(n,d,100), 3, '000')
[d,n,e] = arl2(v,d,8)
plot2d([], ldiv(n,d,100), 5, '000')

[d,n,e] = arl2(v,poly(1,'z','c'),4,'all')
plot2d([], ldiv(n(1),d(1),100), 10, '000')

In NWNI

v = ones(1,20);
[d,n,e] = arl2(v, poly(1,'z','c'),1)
[d,n,e] = arl2(v,d,3)
[d,n,e] = arl2(v,d,8)