int: wa; int: nt; int: sa; int: q; int: nsw; int: v; int: t; test check(bool: b,string: s) = if b then true else trace_stdout("ERROR: "++s++"\n",false) endif; array[int] of bool: checks = [ check(wa!=nt, "wa and nt have the same colour"), check(wa!=sa, "wa and sa have the same colour"), check(nt!=sa, "nt and sa have the same colour"), check(nt!=q, "nt and q have the same colour"), check(sa!=q, "sa and q have the same colour"), check(sa!=nsw, "sa and nsw have the same colour"), check(sa!=v, "sa and v have the same colour"), check(q!=nsw, "q and nsw have the same colour"), check(nsw!=v, "nsw and v have the same colour") ]; output [ if forall(checks) then "CORRECT: all constraints hold.\n" else "INCORRECT\n" endif ];