reserve i, j, k for Element of NAT,
  I for Element of Segm 8,
  i1, i2 for Element of NAT,
  d1, d2, d3, d4 for Element of SCM-Data-Loc,
  S for non empty 1-sorted;
reserve G for non empty 1-sorted;

theorem
  for s being SCM-State of G, t being Element of SCM-Data-Loc, u being
Element of G, mk being Element of SCM-Data-Loc st mk <> t holds SCM-Chg(s,t,u).
  mk = s.mk
proof
  let s be SCM-State of G, t be Element of SCM-Data-Loc, u be Element of G, mk
  be Element of SCM-Data-Loc such that
A1: mk <> t;
  not mk in dom(t .--> u) by A1,TARSKI:def 1;
  hence thesis by FUNCT_4:11;
end;
