>>762 Io
Io> d:=list(list(1,2,3),list(2,3,4,5),list(1,2,3,4,5))
==> list(list(1, 2, 3), list(2, 3, 4, 5), list(1, 2, 3, 4, 5))
Io> d reduce(a,b,a intersect(b))
==> list(2, 3)