
theorem Th25:
  for C being non empty set, A being MSAlgebra over CatSign C for
  a being Element of C holds Args(idsym(a), A) = {{}}
proof
  let C be non empty set, A be MSAlgebra over CatSign C;
  let a be Element of C;
  thus Args(idsym(a), A) = product ((the Sorts of A)*the_arity_of idsym a) by
PRALG_2:3
    .= product ((the Sorts of A)*{}) by Def3
    .= {{}} by CARD_3:10;
end;
