reserve a,a1,a2,a3,b,b1,b2,b3,r,s,t,u for Real;
reserve n for Nat;
reserve x0,x,x1,x2,x3,y0,y,y1,y2,y3 for Element of REAL n;
reserve L,L0,L1,L2 for Element of line_of_REAL n;

theorem Th63:
  L1 misses L2 implies ex x st x in L1 & not x in L2
proof
  assume
A1: L1 misses L2;
  consider x such that
A2: x in L1 by Th52;
  take x;
  thus thesis by A1,A2,Th49;
end;
