%% auteur : Gilles MORA

-1 5 setxrange
-1 5 setyrange
50 setxunit
50 setyunit
/A{0 4} def
/B{4 4} def
/C {4 0} def
/D {0 0} def
/M{0 3} def
/N{4 3} def
[A B C D] polygone
/K{M B A N interdroite} def
/L{D N C M interdroite} def
[A N] ligne
[B M] ligne
[M C] ligne
[D N] ligne
/fillstyle{.5 setgray fill } def
mixte [M K N L] polygone*
setTimes
(A) A [1.5 1.5] ultext
(B) B [1.5 1.5] urtext
(C) C [1.5 1.5] drtext
(D) D [1.5 1.5] dltext
(K) K [1.5 1.5] utext
(L) L [1.5 1.5] dtext
(M) M [1.5 1.5] ltext
(N) N [1.5 1.5] rtext