Hi,
I ran across a segmentation error with the following
computation:

-10-bash:spurtefix-[~/Prog/Gap]-> bin/mygap 
gap> el:=List([1..4],x->rec(num:=x));
[ rec(
      num := 1 ), rec(
      num := 2 ), rec(
      num := 3 ), rec(
      num := 4 ) ]
gap> bl:=List([1..2],x->rec(num:=x,els:=Filtered(el,e->(e.num+x ) mod 2 =0)));
[ rec(
      num := 1,
      els := [ rec(
              num := 1 ), rec(
              num := 3 ) ] ), rec(
      num := 2,
      els := [ rec(
              num := 2 ), rec(
              num := 4 ) ] ) ]
gap> for b in bl do for e in b.els do e.block:=b; od; od;
gap> Set(bl);
Segmentation fault (core dumped)
-11-bash:spurtefix-[~/Prog/Gap]-> 

I guess, it is due to the recursive nature of the structs, but
I need it to be such. Probably I can do with defining a "<"
relation for the records, but there seems to be a bug in gap
anyway.
Finally I must admit that I run gap 3.4 as of 10 Jul 94 without
any patches. Maybe the problem has disappeared since that.

Andreas