:: Characteristic of Rings; Prime Fields
:: by Christoph Schwarzweller and Artur Korni{\l}owicz
::
:: Received August 14, 2015
:: Copyright (c) 2015-2016 Association of Mizar Users
:: (Stowarzyszenie Uzytkownikow Mizara, Bialystok, Poland).
:: This code can be distributed under the GNU General Public Licence
:: version 3.0 or later, or the Creative Commons Attribution-ShareAlike
:: License version 3.0 or later, subject to the binding interpretation
:: detailed in file COPYING.interpretation.
:: See COPYING.GPL and COPYING.CC-BY-SA for the full text of these
:: licenses, or see http://www.gnu.org/licenses/gpl.html and
:: http://creativecommons.org/licenses/by-sa/3.0/.
environ
vocabularies ARYTM_3, FUNCT_1, RELAT_1, RLVECT_1, VECTSP_1, ALGSTR_0, TARSKI,
INT_1, FUNCT_2, VECTSP_2, VECTSP10, STRUCT_0, SUBSET_1, SUPINF_2, NAT_1,
CARD_1, MESFUNC1, INT_3, GROUP_1, ARYTM_1, ORDINAL1, INT_2, QUOFIELD,
MSSUBFAM, BINOP_1, GROUP_6, MOD_4, LATTICES, NUMBERS, IDEAL_1, C0SP1,
ZFMISC_1, FUNCSDOM, RING_2, FINSET_1, XXREAL_0, WELLORD1, REALSET1,
XBOOLE_0, EC_PF_1, BINOP_2, COMPLFLD, GAUSSINT, XCMPLX_0, REAL_1, RING_3,
RAT_1, NEWTON;
notations TARSKI, XBOOLE_0, ZFMISC_1, SUBSET_1, DOMAIN_1, RELAT_1, FUNCT_1,
RELSET_1, PARTFUN1, ORDINAL1, FUNCT_2, BINOP_1, REALSET1, XCMPLX_0,
XXREAL_0, XREAL_0, CARD_1, BINOP_2, XXREAL_2, NAT_1, INT_1, INT_2, NAT_D,
RAT_1, INT_3, NUMBERS, NEWTON, MATRLIN2, STRUCT_0, MOD_4, BINOM,
ALGSTR_0, GROUP_1, GROUP_6, RLVECT_1, GCD_1, VECTSP_2, VECTSP_1, GR_CY_1,
COMPLFLD, VECTSP10, EC_PF_1, GAUSSINT, IDEAL_1, QUOFIELD, C0SP1, RING_1,
RING_2;
constructors BINOM, QUOFIELD, MOD_4, REALSET1, BINOP_2, GCD_1, RINGCAT1,
XXREAL_2, RING_2, GAUSSINT, GR_CY_1, EC_PF_1, NAT_D, MATRLIN2, TOPALG_7;
registrations ORDINAL1, XXREAL_0, XREAL_0, RELSET_1, VECTSP_1, STRUCT_0,
MEMBERED, NUMBERS, XBOOLE_0, RAT_1, RLVECT_1, INT_1, INT_3, COMPLFLD,
REALSET1, TOPALG_7, GAUSSINT, NAT_1, ALGSTR_1, SUBSET_1, RELAT_1,
FUNCT_2, ALGSTR_0, QUOFIELD, GROUP_6, MOD_4, RINGCAT1, RING_1, C0SP1,
GRCAT_1, XCMPLX_0, XXREAL_2, FOMODEL0, RING_2, NAT_2, FUNCT_1, CARD_1,
EC_PF_1;
requirements NUMERALS, SUBSET, BOOLE, REAL, ARITHM;
begin :: Preliminaries
theorem :: RING_3:1
for f being Function, A being set, a,b being object st a in A & b in A
holds (f||A).(a,b) = f.(a,b);
theorem :: RING_3:2
addcomplex||REAL = addreal;
theorem :: RING_3:3
multcomplex||REAL = multreal;
theorem :: RING_3:4
addrat||INT = addint;
theorem :: RING_3:5
multrat||INT = multint;
begin :: Properties of Fractions
reserve p,q for Rational;
reserve g,m,m1,m2,n,n1,n2 for Nat;
reserve i,i1,i2,j,j1,j2 for Integer;
theorem :: RING_3:6
n divides i implies i div n = i / n;
theorem :: RING_3:7
i div (i gcd n) = i / (i gcd n);
theorem :: RING_3:8
n div (n gcd i) = n / (n gcd i);
theorem :: RING_3:9
g divides i & g divides m implies i / m = (i div g) / (m div g);
theorem :: RING_3:10
i / m = (i div (i gcd m)) / (m div (i gcd m));
theorem :: RING_3:11
0 < m & m*i divides m implies i = 1 or i = -1;
theorem :: RING_3:12
0 < m & m*n divides m implies n = 1;
theorem :: RING_3:13
m divides i implies i div m divides i;
theorem :: RING_3:14
m <> 0 implies (i div (i gcd m)) gcd (m div (i gcd m)) = 1;
theorem :: RING_3:15
m <> 0 implies
denominator(i/m) = m div ( i gcd m ) &
numerator(i/m) = i div ( i gcd m );
theorem :: RING_3:16
m <> 0 implies
denominator(i/m) = m / ( i gcd m ) &
numerator(i/m) = i / ( i gcd m );
theorem :: RING_3:17
m <> 0 implies
denominator -(i/m) = m div ( (-i) gcd m ) &
numerator -(i/m) = (-i) div ( (-i) gcd m );
theorem :: RING_3:18
m <> 0 implies
denominator -(i/m) = m / ( (-i) gcd m ) &
numerator -(i/m) = (-i) / ( (-i) gcd m );
theorem :: RING_3:19
m <> 0 implies
denominator((m/i)") = m div ( m gcd i ) &
numerator((m/i)") = i div ( m gcd i );
theorem :: RING_3:20
m <> 0 implies
denominator((m/i)") = m / ( m gcd i ) &
numerator((m/i)") = i / ( m gcd i );
theorem :: RING_3:21
m <> 0 & n <> 0 implies
denominator(i/m+j/n) = (m*n) div ( (i*n+j*m) gcd (m*n) ) &
numerator(i/m+j/n) = (i*n+j*m) div ( (i*n+j*m) gcd (m*n) );
theorem :: RING_3:22
m <> 0 & n <> 0 implies
denominator(i/m+j/n) = (m*n) / ( (i*n+j*m) gcd (m*n) ) &
numerator(i/m+j/n) = (i*n+j*m) / ( (i*n+j*m) gcd (m*n) );
theorem :: RING_3:23
m <> 0 & n <> 0 implies
denominator(i/m-j/n) = (m*n) div ( (i*n-j*m) gcd (m*n) ) &
numerator(i/m-j/n) = (i*n-j*m) div ( (i*n-j*m) gcd (m*n) );
theorem :: RING_3:24
m <> 0 & n <> 0 implies
denominator(i/m-j/n) = (m*n) / ( (i*n-j*m) gcd (m*n) ) &
numerator(i/m-j/n) = (i*n-j*m) / ( (i*n-j*m) gcd (m*n) );
theorem :: RING_3:25
m <> 0 & n <> 0 implies
denominator((i/m)*(j/n)) = (m*n) div ( (i*j) gcd (m*n) ) &
numerator((i/m)*(j/n)) = (i*j) div ( (i*j) gcd (m*n) );
theorem :: RING_3:26
m <> 0 & n <> 0 implies
denominator((i/m)*(j/n)) = (m*n) / ( (i*j) gcd (m*n) ) &
numerator((i/m)*(j/n)) = (i*j) / ( (i*j) gcd (m*n) );
theorem :: RING_3:27
m <> 0 & n <> 0 implies
denominator((i/m)/(n/j)) = (m*n) div ( (i*j) gcd (m*n) ) &
numerator((i/m)/(n/j)) = (i*j) div ( (i*j) gcd (m*n) );
theorem :: RING_3:28
m <> 0 & n <> 0 implies
denominator((i/m)/(n/j)) = (m*n) / ( (i*j) gcd (m*n) ) &
numerator((i/m)/(n/j)) = (i*j) / ( (i*j) gcd (m*n) );
theorem :: RING_3:29
denominator(p) = denominator(p) div (numerator(p) gcd denominator(p));
theorem :: RING_3:30
numerator(p) = numerator(p) div (numerator(p) gcd denominator(p));
theorem :: RING_3:31
m = denominator p & i = numerator p implies
denominator(-p) = m div ( (-i) gcd m ) &
numerator(-p) = (-i) div ( (-i) gcd m );
theorem :: RING_3:32
m = denominator p & i = numerator p implies
denominator(-p) = m / ( (-i) gcd m ) &
numerator(-p) = (-i) / ( (-i) gcd m );
theorem :: RING_3:33
m = denominator p & n = numerator p & n <> 0 implies
denominator(p") = n div ( n gcd m ) &
numerator(p") = m div ( n gcd m );
theorem :: RING_3:34
m = denominator p & n = numerator p & n <> 0 implies
denominator(p") = n / ( n gcd m ) &
numerator(p") = m / ( n gcd m );
theorem :: RING_3:35
m = denominator p & n = denominator q &
i = numerator p & j = numerator q implies
denominator(p+q) = (m*n) div ( (i*n+j*m) gcd (m*n) ) &
numerator(p+q) = (i*n+j*m) div ( (i*n+j*m) gcd (m*n) );
theorem :: RING_3:36
m = denominator p & n = denominator q &
i = numerator p & j = numerator q implies
denominator(p+q) = (m*n) / ( (i*n+j*m) gcd (m*n) ) &
numerator(p+q) = (i*n+j*m) / ( (i*n+j*m) gcd (m*n) );
theorem :: RING_3:37
m = denominator p & n = denominator q &
i = numerator p & j = numerator q implies
denominator(p-q) = (m*n) div ( (i*n-j*m) gcd (m*n) ) &
numerator(p-q) = (i*n-j*m) div ( (i*n-j*m) gcd (m*n) );
theorem :: RING_3:38
m = denominator p & n = denominator q &
i = numerator p & j = numerator q implies
denominator(p-q) = (m*n) / ( (i*n-j*m) gcd (m*n) ) &
numerator(p-q) = (i*n-j*m) / ( (i*n-j*m) gcd (m*n) );
theorem :: RING_3:39
m = denominator p & n = denominator q &
i = numerator p & j = numerator q implies
denominator(p*q) = (m*n) div ( (i*j) gcd (m*n) ) &
numerator(p*q) = (i*j) div ( (i*j) gcd (m*n) );
theorem :: RING_3:40
m = denominator p & n = denominator q &
i = numerator p & j = numerator q implies
denominator(p*q) = (m*n) / ( (i*j) gcd (m*n) ) &
numerator(p*q) = (i*j) / ( (i*j) gcd (m*n) );
theorem :: RING_3:41
m1 = denominator p & m2 = denominator q &
n1 = numerator p & n2 = numerator q & n2 <> 0 implies
denominator(p/q) = (m1*n2) div ( (n1*m2) gcd (m1*n2) ) &
numerator(p/q) = (n1*m2) div ( (n1*m2) gcd (m1*n2) );
theorem :: RING_3:42
m1 = denominator p & m2 = denominator q &
n1 = numerator p & n2 = numerator q & n2 <> 0 implies
denominator(p/q) = (m1*n2) / ( (n1*m2) gcd (m1*n2) ) &
numerator(p/q) = (n1*m2) / ( (n1*m2) gcd (m1*n2) );
begin :: Preliminaries about Rings and Fields
reserve R for Ring, F for Field;
registration
cluster positive for Element of INT.Ring;
cluster negative for Element of INT.Ring;
end;
registration
let a be non zero Element of F_Rat, x be Rational;
identify a" with x" when a = x;
end;
registration
let a be Element of F_Rat, b be non zero Element of F_Rat;
let x,y be Rational;
identify a/b with x/y when a = x, b = y;
end;
registration
let F be Field;
reduce (1.F)" to 1.F;
end;
definition
let R,S be Ring;
pred R includes_an_isomorphic_copy_of S means
:: RING_3:def 1
ex T being strict Subring of R st T,S are_isomorphic;
end;
notation
let R,S be Ring;
synonym R includes S for R includes_an_isomorphic_copy_of S;
end;
definition
let R,S be Ring;
redefine pred R,S are_isomorphic;
reflexivity;
end;
theorem :: RING_3:43
for E being Field, F being Subfield of E holds F is Subring of E;
theorem :: RING_3:44
for R,S,T being Ring
st R,S are_isomorphic & S,T are_isomorphic holds R,T are_isomorphic;
theorem :: RING_3:45
for F being Field,
R being Subring of F holds R is Subfield of F iff R is Field;
theorem :: RING_3:46
for E being Field, F being strict Subfield of E holds E includes F;
theorem :: RING_3:47
INT.Ring is Subring of F_Rat;
theorem :: RING_3:48
F_Real is Subfield of F_Complex;
registration
let R be domRing;
cluster R-homomorphic for domRing;
cluster R-homomorphic for comRing;
cluster R-homomorphic for Ring;
end;
registration
let R be Field;
cluster R-homomorphic for domRing;
end;
registration
let F be Field,
R be F-homomorphic Ring,
f be Homomorphism of F,R;
cluster Image f -> almost_left_invertible;
end;
registration
let F be domRing,
E be F-homomorphic domRing,
f be Homomorphism of F,E;
cluster Image f -> non degenerated;
end;
theorem :: RING_3:49
for R being Ring, E being R-homomorphic Ring, K being Subring of R
for f being Function of R,E, g being Function of K,E st
g = f|(the carrier of K) & f is additive
holds g is additive;
theorem :: RING_3:50
for R being Ring, E being R-homomorphic Ring, K being Subring of R
for f being Function of R,E, g being Function of K,E st
g = f|(the carrier of K) & f is multiplicative
holds g is multiplicative;
theorem :: RING_3:51
for R being Ring, E being R-homomorphic Ring, K being Subring of R
for f being Function of R,E, g being Function of K,E st
g = f|(the carrier of K) & f is unity-preserving
holds g is unity-preserving;
theorem :: RING_3:52
for R being Ring, E being R-homomorphic Ring, K being Subring of R holds
E is K-homomorphic;
theorem :: RING_3:53
for R being Ring,
E being R-homomorphic Ring,
K being Subring of R,
EK being K-homomorphic Ring
for f being Homomorphism of R,E st E = EK holds f|K is Homomorphism of K,EK;
theorem :: RING_3:54
for F being Field, E being F-homomorphic Field, K being Subfield of F
for f being Function of F,E, g being Function of K,E st
g = f|(the carrier of K) & f is additive
holds g is additive;
theorem :: RING_3:55
for F being Field, E being F-homomorphic Field, K being Subfield of F
for f being Function of F,E, g being Function of K,E st
g = f|(the carrier of K) & f is multiplicative
holds g is multiplicative;
theorem :: RING_3:56
for F being Field, E being F-homomorphic Field, K being Subfield of F
for f being Function of F,E, g being Function of K,E st
g = f|(the carrier of K) & f is unity-preserving
holds g is unity-preserving;
theorem :: RING_3:57
for F being Field, E being F-homomorphic Field, K being Subfield of F holds
E is K-homomorphic;
theorem :: RING_3:58
for F being Field,
E being F-homomorphic Field,
K being Subfield of F,
EK being K-homomorphic Field
for f being Homomorphism of F,E st E = EK holds f|K is Homomorphism of K,EK;
notation
let n be Nat;
synonym Z/n for INT.Ring n;
end;
registration
let n be Nat;
cluster Z/n -> finite;
end;
registration
let n be non trivial Nat;
cluster Z/n -> non degenerated;
end;
registration
let n be positive Nat;
cluster Z/n -> Abelian add-associative right_zeroed right_complementable;
end;
registration
let n be positive Nat;
cluster Z/n -> associative well-unital distributive commutative;
end;
registration
let p be Prime;
cluster Z/p -> almost_left_invertible;
end;
begin :: Embedding the Integers in Rings
definition
let R be add-associative right_zeroed right_complementable
non empty doubleLoopStr,
a be Element of R,
i be Integer;
func i '*' a -> Element of R means
:: RING_3:def 2
ex n being Nat st (i = n & it = n*a) or (i = -n & it = -(n*a));
end;
theorem :: RING_3:59
for R being add-associative right_zeroed right_complementable
non empty doubleLoopStr,
a being Element of R holds 0 '*' a = 0.R;
theorem :: RING_3:60
for R being add-associative right_zeroed right_complementable
non empty doubleLoopStr,
a being Element of R holds 1 '*' a = a;
theorem :: RING_3:61
for R being add-associative right_zeroed right_complementable
non empty doubleLoopStr,
a being Element of R holds (-1) '*' a = -a;
theorem :: RING_3:62
for R being add-associative right_zeroed right_complementable
Abelian non empty doubleLoopStr,
a being Element of R,
i,j being Integer holds (i + j) '*' a = i '*' a + j '*' a;
theorem :: RING_3:63
for R being add-associative right_zeroed right_complementable
Abelian non empty doubleLoopStr,
a being Element of R,
i being Integer holds (-i) '*' a = -(i '*' a);
theorem :: RING_3:64
for R being add-associative right_zeroed right_complementable
Abelian non empty doubleLoopStr,
a being Element of R,
i,j being Integer holds (i - j) '*' a = i '*' a - j '*' a;
theorem :: RING_3:65
for R being add-associative right_zeroed right_complementable
Abelian non empty doubleLoopStr,
a being Element of R,
i,j being Integer holds (i * j) '*' a = i '*' (j '*' a);
theorem :: RING_3:66
for R being add-associative right_zeroed right_complementable
Abelian non empty doubleLoopStr,
a being Element of R,
i,j being Integer holds i '*' (j '*' a) = j '*' (i '*' a);
theorem :: RING_3:67
for R being add-associative right_zeroed right_complementable
Abelian left_unital distributive non empty doubleLoopStr,
i,j being Integer holds (i * j) '*' 1.R = (i '*' 1.R) * (j '*' 1.R);
theorem :: RING_3:68
for R being Ring, S being R-homomorphic Ring, f being Homomorphism of R,S
for a being Element of R,
i being Integer holds f.(i '*' a) = i '*' f.a;
begin :: Mono- and Isomorphisms of Rings
definition
let R,S be Ring;
attr S is R-monomorphic means
:: RING_3:def 3
ex f being Function of R,S st f is RingHomomorphism monomorphism;
end;
registration
let R be Ring;
cluster R-monomorphic for Ring;
end;
registration
let R be comRing;
cluster R-monomorphic for comRing;
cluster R-monomorphic for Ring;
end;
registration
let R be domRing;
cluster R-monomorphic for domRing;
cluster R-monomorphic for comRing;
cluster R-monomorphic for Ring;
end;
registration
let R be Field;
cluster R-monomorphic for Field;
cluster R-monomorphic for domRing;
cluster R-monomorphic for comRing;
cluster R-monomorphic for Ring;
end;
registration
let R be Ring,
S be R-monomorphic Ring;
cluster additive multiplicative unity-preserving monomorphism
for Function of R,S;
end;
definition
let R be Ring,
S be R-monomorphic Ring;
mode Monomorphism of R,S is additive multiplicative unity-preserving
monomorphism Function of R,S;
end;
registration
let R be Ring,
S be R-monomorphic Ring;
cluster -> R-monomorphic for S-monomorphic Ring;
end;
registration
let R be Ring;
cluster -> R-homomorphic for R-monomorphic Ring;
end;
registration
let R be Ring;
let S be R-monomorphic Ring;
let f be Monomorphism of R,S;
reduce (f")" to f;
end;
theorem :: RING_3:69
for R being Ring,
S being R-homomorphic Ring, T being S-homomorphic Ring
for f being Homomorphism of R,S
for g being Homomorphism of S,T holds ker(f) c= ker(g*f);
theorem :: RING_3:70
for R being Ring,
S being R-homomorphic Ring, T being S-monomorphic Ring
for f being Homomorphism of R,S
for g being Monomorphism of S,T holds ker(f) = ker(g*f);
theorem :: RING_3:71
for R being Ring, S being Subring of R holds R is S-monomorphic;
theorem :: RING_3:72
for R,S being Ring holds S is R-monomorphic Ring iff S includes R;
definition
let R,S be Ring;
attr S is R-isomorphic means
:: RING_3:def 4
ex f being Function of R,S st f is RingHomomorphism isomorphism;
end;
registration
let R be Ring;
cluster R-isomorphic for Ring;
end;
registration
let R be comRing;
cluster R-isomorphic for comRing;
cluster R-isomorphic for Ring;
end;
registration
let R be domRing;
cluster R-isomorphic for domRing;
cluster R-isomorphic for comRing;
cluster R-isomorphic for Ring;
end;
registration
let R be Field;
cluster R-isomorphic for Field;
cluster R-isomorphic for domRing;
cluster R-isomorphic for comRing;
cluster R-isomorphic for Ring;
end;
registration
let R be Ring,
S be R-isomorphic Ring;
cluster additive multiplicative unity-preserving
isomorphism for Function of R,S;
end;
definition
let R be Ring,
S be R-isomorphic Ring;
mode Isomorphism of R,S is additive multiplicative unity-preserving
isomorphism Function of R,S;
end;
definition
let R be Ring;
let S be R-isomorphic Ring;
let f be Isomorphism of R,S;
redefine func f" -> Function of S,R;
end;
registration
let R be Ring,
S be R-isomorphic Ring;
cluster additive multiplicative unity-preserving
isomorphism for Function of S,R;
end;
definition
let R be Ring,
S be R-isomorphic Ring;
mode Isomorphism of S,R is additive multiplicative unity-preserving
isomorphism Function of S,R;
end;
registration
let R be Ring,
S be R-isomorphic Ring;
cluster -> R-isomorphic for S-isomorphic Ring;
end;
registration
let R be Ring;
cluster -> R-monomorphic for R-isomorphic Ring;
end;
theorem :: RING_3:73
for R being Ring, S being R-isomorphic Ring,
f being Isomorphism of R,S holds f" is Isomorphism of S,R;
theorem :: RING_3:74
for R being Ring, S being R-isomorphic Ring holds R is S-isomorphic;
registration
let R be comRing;
cluster -> commutative for R-isomorphic Ring;
end;
registration
let R be domRing;
cluster -> non degenerated domRing-like for R-isomorphic Ring;
end;
registration
let F be Field;
cluster -> almost_left_invertible for F-isomorphic Ring;
end;
theorem :: RING_3:75
for E,F being Field
holds E includes F iff ex K being strict Subfield of E st K,F are_isomorphic;
begin :: Characteristic of Rings
definition
let R be Ring;
func Char R -> Nat means
:: RING_3:def 5
(it '*' 1.R = 0.R & it <> 0 &
for m being positive Nat st m < it holds m '*' 1.R <> 0.R) or
(it = 0 &
for m being positive Nat holds m '*' 1.R <> 0.R);
end;
definition
let n be Nat;
let R be Ring;
attr R is n-characteristic means
:: RING_3:def 6
Char R = n;
end;
theorem :: RING_3:76
Char(INT.Ring) = 0;
theorem :: RING_3:77
for n being positive Nat holds Char(Z/n) = n;
registration
cluster INT.Ring -> 0-characteristic;
end;
registration
let n be positive Nat;
cluster Z/n -> n-characteristic;
end;
registration
let n be Nat;
cluster n-characteristic for comRing;
end;
registration
let n be positive Nat;
let R be n-characteristic Ring;
cluster Char R -> positive;
end;
definition
let R be Ring;
func CharSet R -> Subset of NAT equals
:: RING_3:def 7
{ n where n is positive Nat : n '*' 1.R = 0.R };
end;
registration
let n be positive Nat,
R be n-characteristic Ring;
cluster CharSet R -> non empty;
end;
theorem :: RING_3:78
for R being Ring holds Char R = 0 iff CharSet R = {};
theorem :: RING_3:79
for n being positive Nat,
R being n-characteristic Ring holds Char R = min(CharSet R);
theorem :: RING_3:80
for R being Ring holds Char R = min*(CharSet R);
theorem :: RING_3:81
for p being Prime,
R being p-characteristic Ring,
n being positive Nat
holds n is Element of CharSet R iff p divides n;
definition
let R be Ring;
func canHom_Int R -> Function of INT.Ring,R means
:: RING_3:def 8
for x being Element of INT.Ring holds it.x = x '*' 1.R;
end;
registration
let R be Ring;
cluster canHom_Int R -> additive multiplicative unity-preserving;
end;
registration
cluster -> (INT.Ring)-homomorphic for Ring;
end;
theorem :: RING_3:82
for R being Ring,
n being non negative Element of INT.Ring
holds Char R = n iff ker(canHom_Int R) = {n}-Ideal;
theorem :: RING_3:83
for R being Ring holds Char R = 0 iff canHom_Int R is monomorphism;
registration
let R be 0-characteristic Ring;
cluster canHom_Int R -> monomorphism;
end;
registration
let R be 0-characteristic Ring;
cluster additive multiplicative unity-preserving monomorphism for
Function of INT.Ring,R;
end;
theorem :: RING_3:84
for R being Ring, f being Homomorphism of INT.Ring,R holds f = canHom_Int R;
theorem :: RING_3:85
for f being Homomorphism of INT.Ring,INT.Ring holds f = id INT.Ring;
theorem :: RING_3:86
for R being domRing holds Char R = 0 or Char R is prime;
theorem :: RING_3:87
for R being Ring, S being R-homomorphic Ring holds Char S divides Char R;
theorem :: RING_3:88
for R being Ring, S being R-monomorphic Ring holds Char S = Char R;
theorem :: RING_3:89
for R being Ring, S being Subring of R holds Char S = Char R;
registration
let n be Nat;
let R be n-characteristic Ring;
cluster R-monomorphic -> n-characteristic for Ring;
cluster -> n-characteristic for Subring of R;
end;
registration
cluster F_Complex -> 0-characteristic;
end;
registration
cluster F_Real -> 0-characteristic;
end;
registration
cluster F_Rat -> 0-characteristic;
end;
registration
cluster 0-characteristic for Field;
end;
registration
let p be Prime;
cluster p-characteristic for Field;
end;
registration
let p be Prime;
let R be p-characteristic domRing;
cluster Char R -> prime;
end;
registration
let F be 0-characteristic Field;
cluster -> 0-characteristic for Subfield of F;
end;
registration
let p be Prime;
let F be p-characteristic Field;
cluster -> p-characteristic for Subfield of F;
end;
begin :: Prime Fields
definition
let F be Field;
func carrier/\ F -> Subset of F equals
:: RING_3:def 9
{x where x is Element of F : for K being Subfield of F holds x in K};
end;
definition
let F be Field;
func PrimeField F -> strict doubleLoopStr means
:: RING_3:def 10
the carrier of it = carrier/\ F &
the addF of it = (the addF of F)||(carrier/\ F) &
the multF of it = (the multF of F)||(carrier/\ F) &
the OneF of it = 1.F &
the ZeroF of it = 0.F;
end;
registration
let F be Field;
cluster PrimeField F -> non degenerated;
end;
registration
let F be Field;
cluster PrimeField F -> Abelian
add-associative right_zeroed right_complementable;
end;
registration
let F be Field;
cluster PrimeField F -> commutative;
end;
registration
let F be Field;
cluster PrimeField F -> associative well-unital
distributive almost_left_invertible;
end;
definition
let F be Field;
redefine func PrimeField F -> strict Subfield of F;
end;
theorem :: RING_3:90
for F being Field,
E being strict Subfield of PrimeField F holds E = PrimeField F;
theorem :: RING_3:91
for F being Field, E being Subfield of F holds PrimeField F is Subfield of E;
theorem :: RING_3:92
for F,K being Field holds
K = PrimeField F iff (K is strict Subfield of F &
for E being strict Subfield of K holds E = K);
theorem :: RING_3:93
for F,K being Field holds
K = PrimeField F iff (K is strict Subfield of F &
for E being Subfield of F holds K is Subfield of E);
theorem :: RING_3:94
for E being Field, F being Subfield of E holds PrimeField F = PrimeField E;
theorem :: RING_3:95
for F being Field holds PrimeField(PrimeField F) = PrimeField F;
registration
let F be Field;
cluster PrimeField F -> prime;
end;
theorem :: RING_3:96
for F being Field holds F is prime iff F = PrimeField F;
theorem :: RING_3:97
for F being 0-characteristic Field,
i,j being non zero Integer st j divides i
holds (i div j) '*' 1.F = (i '*' 1.F) * (j '*' 1.F)";
definition
let x be Element of F_Rat;
redefine func denominator(x) -> positive Element of INT.Ring;
redefine func numerator(x) -> Element of INT.Ring;
end;
definition
let F be Field;
func canHom_Rat F -> Function of F_Rat,F means
:: RING_3:def 11
for x being Element of F_Rat holds
it.x = ((canHom_Int F).numerator x) / ((canHom_Int F).denominator x);
end;
registration
let F be Field;
cluster canHom_Rat F -> unity-preserving;
end;
registration
let F be 0-characteristic Field;
cluster canHom_Rat F -> additive multiplicative;
end;
registration
cluster -> (F_Rat)-monomorphic for 0-characteristic Field;
end;
theorem :: RING_3:98
for F being Field holds canHom_Int F = (canHom_Rat F) | INT;
registration
cluster 0-characteristic F_Rat-homomorphic for Field;
end;
theorem :: RING_3:99
for F being 0-characteristic F_Rat-homomorphic Field,
f being Homomorphism of F_Rat,F holds f = canHom_Rat F;
registration
cluster F_Rat -> F_Rat-homomorphic;
end;
registration
let F be 0-characteristic Field;
cluster PrimeField F -> F_Rat-homomorphic;
end;
theorem :: RING_3:100
for f being Homomorphism of F_Rat,F_Rat holds f = id F_Rat;
definition
let F be Field,
S be F-homomorphic Field,
f be Homomorphism of F,S;
redefine func Image f -> strict Subfield of S;
end;
registration
let F be 0-characteristic Field;
cluster canHom_Rat PrimeField F -> onto;
end;
theorem :: RING_3:101
for F being 0-characteristic Field holds F_Rat,PrimeField F are_isomorphic;
theorem :: RING_3:102
PrimeField F_Rat = F_Rat;
theorem :: RING_3:103
for F being 0-characteristic Field holds F includes F_Rat;
theorem :: RING_3:104
for F being 0-characteristic Field,
E being Field st F includes E holds E includes F_Rat;
theorem :: RING_3:105
for p being Prime, R being p-characteristic Ring,
i being Integer
holds i '*' 1.R = (i mod p) '*' 1.R;
definition
let p be Prime,
F be Field;
func canHom_Z/(p,F) -> Function of Z/p,F equals
:: RING_3:def 12
(canHom_Int F) | (the carrier of Z/p);
end;
registration
let p be Prime,
F be Field;
cluster canHom_Z/(p,F) -> unity-preserving;
end;
registration
let p be Prime,
F be p-characteristic Field;
cluster canHom_Z/(p,F) -> additive multiplicative;
end;
registration
let p be Prime;
cluster -> (Z/p)-monomorphic for p-characteristic Field;
end;
registration
let p be Prime;
cluster p-characteristic (Z/p)-homomorphic for Field;
cluster Z/p -> (Z/p)-homomorphic;
end;
theorem :: RING_3:106
for p being Prime,
F being p-characteristic (Z/p)-homomorphic Field,
f being Homomorphism of Z/p,F holds f = canHom_Z/(p,F);
theorem :: RING_3:107
for p being Prime,
f being Homomorphism of Z/p,Z/p holds f = id Z/p;
registration
let p be Prime, F be p-characteristic Field;
cluster PrimeField F -> Z/p-homomorphic;
end;
registration
let p be Prime, F be p-characteristic Field;
cluster canHom_Z/(p,PrimeField F) -> onto;
end;
theorem :: RING_3:108
for p being Prime,
F being p-characteristic Field holds Z/p,PrimeField F are_isomorphic;
theorem :: RING_3:109
for p being Prime, F being strict Subfield of Z/p holds F = Z/p;
theorem :: RING_3:110
for p being Prime holds PrimeField Z/p = Z/p;
theorem :: RING_3:111
for p being Prime,
F being p-characteristic Field holds F includes Z/p;
theorem :: RING_3:112
for p being Prime,
F being p-characteristic Field,
E being Field st F includes E holds E includes Z/p;
registration
let p be Prime;
cluster Z/p -> prime;
end;
theorem :: RING_3:113
for F being Field
holds Char F = 0 iff PrimeField F, F_Rat are_isomorphic;
theorem :: RING_3:114
for p being Prime,
F being Field
holds Char F = p iff PrimeField F, Z/p are_isomorphic;
theorem :: RING_3:115
for F being strict Field
holds F is prime iff (F,F_Rat are_isomorphic or
ex p being Prime st F,Z/p are_isomorphic);