language Essence 1.3 letting deck_width be 5 letting deck_length be 5 letting n_containers be 4 letting n_classes be 2 letting width be function( 1 --> 5, 2 --> 2, 3 --> 3 ) letting length be function( 1 --> 1, 2 --> 4, 3 --> 4 ) letting class be function( 1 --> 1, 2 --> 1, 3 --> 1) letting separation be function ( {1,2} --> 0 )