$ clisp <...snip...> [1]> (load "quarto.l") ;; Loading file quarto.l ... ;; Loading file lp.l ... ;; Loaded file lp.l ;; Loaded file quarto.l T [2]> (task77--available-locations-demo) Available spaces on an empty board: (A1 A2 A3 A4 B1 B2 B3 B4 C1 C2 C3 C4 D1 D2 D3 D4) Available spaces on a board with major diagonal filled: (A2 A3 A4 B1 B3 B4 C1 C2 C4 D1 D2 D3) NIL [3]> (bye) Bye.