
theorem
  for n being Nat, f being Function of n-tuples_on BOOLEAN, BOOLEAN for
  p being FinSeqLen of n holds 1GateCircuit(p,f) is Boolean
proof
  let n be Nat, f be Function of n-tuples_on BOOLEAN, BOOLEAN;
  let p be FinSeqLen of n;
  set S = 1GateCircStr(p,f), A = 1GateCircuit(p,f);
  let v be Vertex of S;
  the Sorts of A = (the carrier of S) --> BOOLEAN by Def13;
  hence thesis;
end;
