We present three classes of abstract prearithmetics,
,
, and
. The
first is weakly projective with respect to the nonnegative real Diophantine arithmetic
, the
second is weakly projective with respect to the real Diophantine arithmetic
, while
the third is exactly projective with respect to the extended real Diophantine arithmetic
. In addition, we
have that every
and every
is a complete totally ordered semiring, while every
is not. We show that the projection of any series of elements of
converges
in
, for
any
,
and that the projection of any nonindeterminate series of elements of
converges
in
, for
any
, and
in
, for all
. We also prove
that working in
and in
,
for any
,
and in
,
for all
,
allows us to overcome a version of the paradox of the heap.
Keywords
non-Diophantine arithmetics, convergence of series, paradox
of the heap