reserve k,n,i,j for Nat;

theorem Th5:
  for D being non empty set, f being FinSequence of D, k2 being
  Nat st 1<=k2 & k2< len f holds f = mid(f,1,k2)^mid(f,k2+1,len f)
proof
  let D be non empty set, f be FinSequence of D, k2 be Nat;
  assume
A1: 1<=k2 & k2< len f;
  then mid(f,1,len f) = mid(f,1,k2)^mid(f,k2+1,len f) by INTEGRA2:4;
  hence thesis by A1,FINSEQ_6:120,XXREAL_0:2;
end;
