reserve X for ARS, a,b,c,u,v,w,x,y,z for Element of X;
reserve i,j,k for Element of ARS_01;
reserve l,m,n for Element of ARS_02;
reserve A for set;

theorem Lm11:
  x ==> y & x ==> z implies y <<01>> z
  proof
    assume
A1: x ==> y;
    assume
A2: x ==> z;
    take x;
    thus y <=01= x by A1;
    thus x =01=> z by A2;
  end;
