:: ARYTM_1 semantic presentation

begin

theorem :: ARYTM_1:1
for x, y being ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) st x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) + y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) = y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) holds
x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) = {} : ( ( ) ( ) Element of RAT+ : ( ( ) ( ) set ) ) ;

theorem :: ARYTM_1:2
for x, y being ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) holds
( not x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) *' y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) = {} : ( ( ) ( ) Element of RAT+ : ( ( ) ( ) set ) ) or x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) = {} : ( ( ) ( ) Element of RAT+ : ( ( ) ( ) set ) ) or y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) = {} : ( ( ) ( ) Element of RAT+ : ( ( ) ( ) set ) ) ) ;

theorem :: ARYTM_1:3
for x, y, z being ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) st x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) <=' y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) & y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) <=' z : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) holds
x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) <=' z : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) ;

theorem :: ARYTM_1:4
for x, y being ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) st x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) <=' y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) & y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) <=' x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) holds
x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) = y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) ;

theorem :: ARYTM_1:5
for x, y being ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) st x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) <=' y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) & y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) = {} : ( ( ) ( ) Element of RAT+ : ( ( ) ( ) set ) ) holds
x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) = {} : ( ( ) ( ) Element of RAT+ : ( ( ) ( ) set ) ) ;

theorem :: ARYTM_1:6
for x, y being ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) st x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) = {} : ( ( ) ( ) Element of RAT+ : ( ( ) ( ) set ) ) holds
x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) <=' y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) ;

theorem :: ARYTM_1:7
for x, y, z being ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) holds
( x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) <=' y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) iff x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) + z : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) <=' y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) + z : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) ) ;

theorem :: ARYTM_1:8
for x, y, z being ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) st x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) <=' y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) holds
x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) *' z : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) <=' y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) *' z : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) ;

definition
let x, y be ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) ;
func x -' y -> ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) means :: ARYTM_1:def 1
it : ( ( ) ( ) Element of K6(x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) ) : ( ( ) ( ) set ) ) + y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) = x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) if y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) <=' x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) )
otherwise it : ( ( ) ( ) Element of K6(x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) ) : ( ( ) ( ) set ) ) = {} : ( ( ) ( ) Element of RAT+ : ( ( ) ( ) set ) ) ;
end;

theorem :: ARYTM_1:9
for x, y being ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) holds
( x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) <=' y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) or x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) -' y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) <> {} : ( ( ) ( ) Element of RAT+ : ( ( ) ( ) set ) ) ) ;

theorem :: ARYTM_1:10
for x, y being ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) st x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) <=' y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) & y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) -' x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) = {} : ( ( ) ( ) Element of RAT+ : ( ( ) ( ) set ) ) holds
x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) = y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) ;

theorem :: ARYTM_1:11
for x, y being ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) holds x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) -' y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) <=' x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) ;

theorem :: ARYTM_1:12
for y, x, z being ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) st y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) <=' x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) & y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) <=' z : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) holds
x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) + (z : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) -' y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) ) : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) = (x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) -' y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) ) : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) + z : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) ;

theorem :: ARYTM_1:13
for z, y, x being ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) st z : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) <=' y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) holds
x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) + (y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) -' z : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) ) : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) = (x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) + y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) ) : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) -' z : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) ;

theorem :: ARYTM_1:14
for z, x, y being ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) st z : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) <=' x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) & y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) <=' z : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) holds
(x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) -' z : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) ) : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) + y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) = x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) -' (z : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) -' y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) ) : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) ;

theorem :: ARYTM_1:15
for y, x, z being ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) st y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) <=' x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) & y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) <=' z : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) holds
(z : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) -' y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) ) : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) + x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) = (x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) -' y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) ) : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) + z : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) ;

theorem :: ARYTM_1:16
for x, y, z being ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) st x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) <=' y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) holds
z : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) -' y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) <=' z : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) -' x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) ;

theorem :: ARYTM_1:17
for x, y, z being ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) st x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) <=' y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) holds
x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) -' z : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) <=' y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) -' z : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) ;

definition
let x, y be ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) ;
func x - y -> ( ( ) ( ) set ) equals :: ARYTM_1:def 2
x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) -' y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) if y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) <=' x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) )
otherwise [{} : ( ( ) ( ) Element of RAT+ : ( ( ) ( ) set ) ) ,(y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) -' x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) ) : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) ] : ( ( ) ( ) set ) ;
end;

theorem :: ARYTM_1:18
for x being ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) holds x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) - x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) = {} : ( ( ) ( ) Element of RAT+ : ( ( ) ( ) set ) ) ;

theorem :: ARYTM_1:19
for x, y being ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) st x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) = {} : ( ( ) ( ) Element of RAT+ : ( ( ) ( ) set ) ) & y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) <> {} : ( ( ) ( ) Element of RAT+ : ( ( ) ( ) set ) ) holds
x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) - y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) = [{} : ( ( ) ( ) Element of RAT+ : ( ( ) ( ) set ) ) ,y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) ] : ( ( ) ( ) set ) ;

theorem :: ARYTM_1:20
for z, y, x being ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) st z : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) <=' y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) holds
x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) + (y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) -' z : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) ) : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) = (x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) + y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) ) : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) - z : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) ;

theorem :: ARYTM_1:21
for z, y, x being ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) st not z : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) <=' y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) holds
x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) - (z : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) -' y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) ) : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) = (x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) + y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) ) : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) - z : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) ;

theorem :: ARYTM_1:22
for y, x, z being ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) st y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) <=' x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) & not y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) <=' z : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) holds
x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) - (y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) -' z : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) ) : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) = (x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) -' y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) ) : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) + z : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) ;

theorem :: ARYTM_1:23
for y, x, z being ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) st not y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) <=' x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) & not y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) <=' z : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) holds
x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) - (y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) -' z : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) ) : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) = z : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) - (y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) -' x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) ) : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) ;

theorem :: ARYTM_1:24
for y, x, z being ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) st y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) <=' x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) holds
x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) - (y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) + z : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) ) : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) = (x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) -' y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) ) : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) - z : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) ;

theorem :: ARYTM_1:25
for x, y, z being ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) st x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) <=' y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) & z : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) <=' y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) holds
(y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) -' z : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) ) : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) - x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) = (y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) -' x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) ) : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) - z : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) ;

theorem :: ARYTM_1:26
for z, y, x being ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) st z : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) <=' y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) holds
x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) *' (y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) -' z : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) ) : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) = (x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) *' y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) ) : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) - (x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) *' z : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) ) : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) ;

theorem :: ARYTM_1:27
for z, y, x being ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) st not z : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) <=' y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) & x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) <> {} : ( ( ) ( ) Element of RAT+ : ( ( ) ( ) set ) ) holds
[{} : ( ( ) ( ) Element of RAT+ : ( ( ) ( ) set ) ) ,(x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) *' (z : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) -' y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) ) : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) ) : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) ] : ( ( ) ( ) set ) = (x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) *' y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) ) : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) - (x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) *' z : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) ) : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) ;

theorem :: ARYTM_1:28
for y, z, x being ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) st y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) -' z : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) <> {} : ( ( ) ( ) Element of RAT+ : ( ( ) ( ) set ) ) & z : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) <=' y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) & x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) <> {} : ( ( ) ( ) Element of RAT+ : ( ( ) ( ) set ) ) holds
(x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) *' z : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) ) : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) - (x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) *' y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) ) : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) : ( ( ) ( ) set ) = [{} : ( ( ) ( ) Element of RAT+ : ( ( ) ( ) set ) ) ,(x : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) *' (y : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) -' z : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) ) : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) ) : ( ( ) ( ) Element of REAL+ : ( ( ) ( ) set ) ) ] : ( ( ) ( ) set ) ;