"sublist_indices" with "map" output



Hello,

In this maxima code:

l:[1, 2, 3, 4];
m:map(lambda([x],x-1.1),l);
sublist_indices(m,lambda ([x], x=-0.1));
sublist_indices(m,lambda ([x], x=0.9));
sublist_indices(m,lambda ([x], x=1.9));
sublist_indices(m,lambda ([x], x=2.9));

why the first and second sublist_indices cannot find the -0.1 and 0.9 values,
whereas the third and fourth sublist_indices can find the 1.9 and 2.9 values?

(%i2)                          l : [1, 2, 3, 4]
(%o2)                            [1, 2, 3, 4]
(%i3)                  m : map(lambda([x], x - 1.1), l)
(%o3)                       [- 0.1, 0.9, 1.9, 2.9]
(%i4)             sublist_indices(m, lambda([x], x = - 0.1))
(%o4)                                 []
(%i5)              sublist_indices(m, lambda([x], x = 0.9))
(%o5)                                 []
(%i6)              sublist_indices(m, lambda([x], x = 1.9))
(%o6)                                 [3]
(%i7)              sublist_indices(m, lambda([x], x = 2.9))
(%o7)                                 [4]

Thanks in advance
Aitor