tensor(list of Lists) produces something useless

[pzinn]

This is not good:

i1 : tensor({1,2,3},{4,5,6},{7,8,9})

o1 = {((1, 4), 7), ((1, 4), 8), ((1, 4), 9), ((1, 5), 7), ((1, 5), 8), ((1, 5), 9), ((1, 6), 7), ((1, 6), 8), ((1, 6), 9), ((2, 4), 7), ((2, 4), 8), ((2, 4), 9), ((2,
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     5), 7), ((2, 5), 8), ((2, 5), 9), ((2, 6), 7), ((2, 6), 8), ((2, 6), 9), ((3, 4), 7), ((3, 4), 8), ((3, 4), 9), ((3, 5), 7), ((3, 5), 8), ((3, 5), 9), ((3, 6),
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     7), ((3, 6), 8), ((3, 6), 9)}

o1 : List

What we should get, ideally, is triples of elements.

Relatedly, there should be a List^**ZZ that produces tuples of elements of a list.

[mahrud]

I think this makes sense, but just pointing out that even for modules tensor currently works pairwise:

i6 : formation tensor(ZZ^1, ZZ^1, ZZ^1)

               1    1
o6 = tensor (ZZ , ZZ )

o6 : Expression of class FunctionApplication

I have a vague memory of trying to change this when I made tensor a left-associative binary operator in 8950020, but I think that broke things? I don't remember.

Regardless, the way to do this should be similar to how Module.directSum and Module.intersect takes care of direct summing or intersecting multiple modules at once.

I would like List^**ZZ as well.