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My GAP version is 3.4.4.

I'm using recursively defined lists, i.e. objects of this kind:

gap> a:=[];; b:=[a];; a[1]:=b;; gap> a; b; [ [ ~ ] ] [ [ ~ ] ]

I found that the basic operations don't work with these lists. For example:

gap> a=b;

causes to run out of memory. The same for:

gap> a:=[3,~]; [ 3, ~ ] gap> a*2;

Apparently GAP tries to reach the list 'first elements' following list

structure; but this is, obviously, impossible with recursive definitions.

Now, my question is:

Is my usage of lists supported or it must be considered bad usage

(but recursion is described in the first chapter of the manual...)?

I think that if recursion is to be allowed then the function '=' must at

least report the problem and not cause exiting, wasting all the work made.

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