theorem Th92:
  not <%>E in rng dom (the Tran of TS) implies (x, <%e%> ==>* y,
  <%>E, TS implies x, <%e%> ==>. y, <%>E, TS)
proof
  assume
A1: not <%>E in rng dom (the Tran of TS);
  assume x, <%e%> ==>* y, <%>E, TS;
  then ==>.-relation(TS) reduces [x, <%e%>], [y, <%>E];
  then [[x, <%e%>], [y, <%>E]] in ==>.-relation(TS) by A1,Th79;
  hence thesis by Def4;
end;
