theorem Th14:
  LeftComp f misses RightComp f
proof
  assume LeftComp f /\ RightComp f <> {};
  then consider x being object such that
A1: x in LeftComp f /\ RightComp f by XBOOLE_0:def 1;
  now
    take x;
    thus x in LeftComp f & x in RightComp f by A1,XBOOLE_0:def 4;
  end;
  then
A2: LeftComp f meets RightComp f by XBOOLE_0:3;
  LeftComp f is_a_component_of (L~f)` & RightComp f is_a_component_of (L~f
  ) ` by GOBOARD9:def 1,def 2;
  hence thesis by A2,GOBOARD9:1,SPRECT_4:6;
end;
