
theorem Th11:
  for L being 1-sorted for A being AlgebraStr over L holds A is Subalgebra of A
proof
  let L be 1-sorted;
  let A be AlgebraStr over L;
  thus the carrier of A c= the carrier of A & 1.A = 1.A & 0.A = 0.A & the addF
of A = (the addF of A)||the carrier of A & the multF of A = (the multF of A)||
  the carrier of A & the lmult of A = (the lmult of A)|[:the carrier of L,the
  carrier of A:];
end;
