theorem Th16:
  for A being finite-yielding non-empty MSAlgebra over S
  for X being SetWithCompoundTerm of S,V
  for g being OperSymbol of X-CircuitStr, o being OperSymbol of S
  st g.{} = [o, the carrier of S] holds Den(g, X-Circuit A) = Den(o,A)
proof
  let A being finite-yielding non-empty MSAlgebra over S;
  let X being SetWithCompoundTerm of S,V;
  let g being OperSymbol of X-CircuitStr, o being OperSymbol of S;
  Den(g, X-Circuit A) = the_action_of (g, A) by Def5
    .= (the Charact of A).(g.{})`1 by Def3;
  hence thesis;
end;
