2 USING: columns sequences kernel namespaces arrays tools.test math ;
5 { { 1 2 3 } { 4 5 6 } { 7 8 9 } } [ clone ] map "seq" set
7 [ { 1 4 7 } ] [ "seq" get 0 <column> >array ] unit-test
8 [ ] [ "seq" get 1 <column> [ sq ] change-each ] unit-test
9 [ { 4 25 64 } ] [ "seq" get 1 <column> >array ] unit-test