
theorem :: Clique1:
for R being RelStr, C being finite Clique of R, n being Nat
  st n <= card C ex B being finite Clique of R st B c= C & card B = n
proof
 let R be RelStr, C be finite Clique of R, n be Nat such that
A1: n <= card C;
   consider BB being finite Subset of C such that
A2: card BB = n by A1,FINSEQ_4:72;
   reconsider BB as finite Clique of R by Th9;
   take BB;
   thus thesis by A2;
end;
