The Antislide-Tetramino or AT-Puzzle was created by the talented Russian designer Vladimir Krasnoukhov for IPP35 (International Puzzle Party) which was hosted in Ottawa, Ontario, Canada in 2015.
This puzzle consists of five tetramino elements and a rectangular frame.
Goal 1: Pack all the elements in such a way that no element can move within the frame ('anti-slide'). Please use the orthogonal grid (graph paper is an example of orthogonal grid). There is only one solution!
Goal 2 (Warming Up): Make a symmetrical shape using all the elements (either inside or outside the frame.)