let R be Ring; for p being Polynomial of R
for r being Real st r in REAL+ holds
p <> r
let p be Polynomial of R; for r being Real st r in REAL+ holds
p <> r
let x be Real; ( x in REAL+ implies p <> x )
assume A1:
x in REAL+
; p <> x
A2:
dom p = NAT
by FUNCT_2:def 1;
then A3:
( [0,(p . 0)] in p & [1,(p . 1)] in p )
by FUNCT_1:def 2;
now not p = xassume A4:
p = x
;
contradictionper cases
( x is Rational or not x is Rational )
;
suppose
x is not
Rational
;
contradictionthen
not
x in RAT
;
then
( not
x in RAT+ \/ [:{0},RAT+:] or
x in {[0,0]} )
by NUMBERS:def 3, XBOOLE_0:def 5;
per cases then
( x in {[0,0]} or ( not x in RAT+ & not x in [:{0},RAT+:] ) )
by XBOOLE_0:def 3;
suppose
( not
x in RAT+ & not
x in [:{0},RAT+:] )
;
contradictionthen
x in DEDEKIND_CUTS
by A1, ARYTM_2:def 2, XBOOLE_0:def 3;
then
(
x in { A where A is Subset of RAT+ : for r being Element of RAT+ st r in A holds
( ( for s being Element of RAT+ st s <=' r holds
s in A ) & ex s being Element of RAT+ st
( s in A & r < s ) ) } & not
x in {RAT+} )
by ARYTM_2:def 1, XBOOLE_0:def 5;
then consider A being
Subset of
RAT+ such that A6:
(
x = A & ( for
r being
Element of
RAT+ st
r in A holds
( ( for
s being
Element of
RAT+ st
s <=' r holds
s in A ) & ex
s being
Element of
RAT+ st
(
s in A &
r < s ) ) ) )
;
consider u being
Element of
A such that A7:
u = [0,(p . 0)]
by A3, A4, A6;
u in A
by A4, A6;
then reconsider u =
u as
Element of
RAT+ ;
per cases
( u in omega or u in { [i,j] where i, j is Element of omega : ( i,j are_coprime & j <> {} ) } \ { [k,1] where k is Element of omega : verum } )
by XBOOLE_0:def 3;
suppose
u in { [i,j] where i, j is Element of omega : ( i,j are_coprime & j <> {} ) } \ { [k,1] where k is Element of omega : verum }
;
contradictionthen A8:
(
u in { [i,j] where i, j is Element of omega : ( i,j are_coprime & j <> {} ) } & not
u in { [k,1] where k is Element of omega : verum } )
by XBOOLE_0:def 5;
then consider i,
j being
Element of
omega such that A9:
(
u = [i,j] &
i,
j are_coprime &
j <> {} )
;
i = 0
by A7, A9, XTUPLE_0:1;
then
j = 1
by A9, ARYTM_3:3;
hence
contradiction
by A8, A9;
verum end; end; end; end; end; end; end;
hence
p <> x
; verum