set c = JsqrtSeries M;
A2:
( dom (JsqrtSeries M) = Bags m & Bags m = dom M )
by FUNCT_2:def 1;
A3:
rng (JsqrtSeries M) c= INT
proof
let y be
object ;
TARSKI:def 3 ( not y in rng (JsqrtSeries M) or y in INT )
assume A4:
y in rng (JsqrtSeries M)
;
y in INT
consider x being
object such that A5:
(
x in dom (JsqrtSeries M) &
(JsqrtSeries M) . x = y )
by A4, FUNCT_1:def 3;
reconsider x =
x as
bag of
m by A5;
per cases
( not x in Support (JsqrtSeries M) or x in Support (JsqrtSeries M) )
;
suppose
x in Support (JsqrtSeries M)
;
y in INT then A6:
(JsqrtSeries M) . x <> 0. F_Complex
by POLYNOM1:def 4;
A7:
(2 (#) x) +* (
0,
(x . 0))
in Bags m
by PRE_POLY:def 12;
A8:
(JsqrtSeries M) . x = M . ((2 (#) x) +* (0,(x . 0)))
by Def12;
then
(2 (#) x) +* (
0,
(x . 0))
in Support M
by A7, A2, A6, POLYNOM1:def 3;
then consider i being
Integer such that A9:
M . ((2 (#) x) +* (0,(x . 0))) = i '*' (1_ F_Complex)
by A1, Def10;
M . ((2 (#) x) +* (0,(x . 0))) = i
by A9, Th1;
hence
y in INT
by A5, A8, INT_1:def 2;
verum end; end;
end;
then
rng (JsqrtSeries M) c= REAL
by NUMBERS:15;
then reconsider r = JsqrtSeries M as Series of m,F_Real by A2, FUNCT_2:2;
A10:
0. F_Complex = 0. F_Real
by COMPLFLD:def 1;
A11:
Support r c= Support (JsqrtSeries M)
reconsider r = r as Polynomial of m,F_Real by A11, POLYNOM1:def 5;
rng r c= INT
by A3;
hence
JsqrtSeries M is INT -valued Polynomial of m,F_Real
by RELAT_1:def 19; verum