reserve h,r,r1,r2,x0,x1,x2,x3,x4,x5,x,a,b,c,k for Real,
  f,f1,f2 for Function of REAL,REAL;

theorem Th14:
  [!(r(#)f),x0,x1,x2,x3,x4,x5!] = r*[!f,x0,x1,x2,x3,x4,x5!]
proof
  [!(r(#)f),x0,x1,x2,x3,x4,x5!] = (r*[!f,x0,x1,x2,x3,x4!] -[!(r(#)f),x1,x2
  ,x3,x4,x5!])/(x0-x5) by Th11
    .= (r*[!f,x0,x1,x2,x3,x4!] -r*[!f,x1,x2,x3,x4,x5!])/(x0-x5) by Th11
    .= (r*([!f,x0,x1,x2,x3,x4!]-[!f,x1,x2,x3,x4,x5!]))/(x0-x5);
  hence thesis by XCMPLX_1:74;
end;
