$ clisp

<...snip...>

[1]> (load "quarto.l")
;; Loading file quarto.l ...
;;  Loading file lp.l ...
;;  Loaded file lp.l
;; Loaded file quarto.l
T
[2]> (task57--similar-pieces-p-demo)
The set ((B+) (R+) (b-)) are similar? T
The set ((B+) (R+) [B-]) are similar? T
The set ((B+) [B+] (b+)) are similar? T
The set ((B+) (R+) (b+)) are similar? T
The set ((B+) (R-) [b+]) are similar? NIL
NIL
[3]> (bye)
Bye.