PRED P(p, q) IS 
  Geometry.Dist(p, q) = 
    Math.Sqrt(2) 
END;

PROC Cmd0() IS 
  IF 
    VAR p ~ (1.1, 1.2) IN 
      P(p, (0, 0)) AND 
      P(p, (2, 0)) AND 
      P(p, (0, 2)) AND 
      P(p, (2, 2)) -> SKIP 
    END 
  FI 
END;

PROC Cmd1() IS 
  VAR s = "SKIP" IN SKIP END 
END;

PROC Cmd2() IS SKIP END;