:: EXTREAL2 semantic presentation

begin

begin

theorem :: EXTREAL2:1
for x being ( ( ) ( ext-real ) R_eal)
for a being ( ( ) ( V11() V12() ext-real ) Real) st x : ( ( ) ( ext-real ) R_eal) = a : ( ( ) ( V11() V12() ext-real ) Real) holds
|.x : ( ( ) ( ext-real ) R_eal) .| : ( ( ) ( ext-real non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) = abs a : ( ( ) ( V11() V12() ext-real ) Real) : ( ( ) ( V11() V12() ext-real ) M2( REAL : ( ( ) ( V1() V30() V38() V39() V40() V44() ) set ) )) ;

theorem :: EXTREAL2:2
for x being ( ( ) ( ext-real ) R_eal) holds
( |.x : ( ( ) ( ext-real ) R_eal) .| : ( ( ) ( ext-real non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) = x : ( ( ) ( ext-real ) R_eal) or |.x : ( ( ) ( ext-real ) R_eal) .| : ( ( ) ( ext-real non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) = - x : ( ( ) ( ext-real ) R_eal) : ( ( ) ( ext-real ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) ) ;

theorem :: EXTREAL2:3
for x being ( ( ) ( ext-real ) R_eal) holds 0 : ( ( ) ( V1() V10() V11() V12() ext-real non positive non negative V38() V39() V40() V41() V42() V43() V44() V81() V82() ) M3( REAL : ( ( ) ( V1() V30() V38() V39() V40() V44() ) set ) , NAT : ( ( ) ( V38() V39() V40() V41() V42() V43() V44() ) M2(K6(REAL : ( ( ) ( V1() V30() V38() V39() V40() V44() ) set ) ) : ( ( ) ( ) set ) )) )) <= |.x : ( ( ) ( ext-real ) R_eal) .| : ( ( ) ( ext-real non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) ;

theorem :: EXTREAL2:4
for x being ( ( ) ( ext-real ) R_eal) st x : ( ( ) ( ext-real ) R_eal) <> 0 : ( ( ) ( V1() V10() V11() V12() ext-real non positive non negative V38() V39() V40() V41() V42() V43() V44() V81() V82() ) M3( REAL : ( ( ) ( V1() V30() V38() V39() V40() V44() ) set ) , NAT : ( ( ) ( V38() V39() V40() V41() V42() V43() V44() ) M2(K6(REAL : ( ( ) ( V1() V30() V38() V39() V40() V44() ) set ) ) : ( ( ) ( ) set ) )) )) holds
0 : ( ( ) ( V1() V10() V11() V12() ext-real non positive non negative V38() V39() V40() V41() V42() V43() V44() V81() V82() ) M3( REAL : ( ( ) ( V1() V30() V38() V39() V40() V44() ) set ) , NAT : ( ( ) ( V38() V39() V40() V41() V42() V43() V44() ) M2(K6(REAL : ( ( ) ( V1() V30() V38() V39() V40() V44() ) set ) ) : ( ( ) ( ) set ) )) )) < |.x : ( ( ) ( ext-real ) R_eal) .| : ( ( ) ( ext-real non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) ;

theorem :: EXTREAL2:5
for x being ( ( ) ( ext-real ) R_eal) holds
( x : ( ( ) ( ext-real ) R_eal) = 0 : ( ( ) ( V1() V10() V11() V12() ext-real non positive non negative V38() V39() V40() V41() V42() V43() V44() V81() V82() ) M3( REAL : ( ( ) ( V1() V30() V38() V39() V40() V44() ) set ) , NAT : ( ( ) ( V38() V39() V40() V41() V42() V43() V44() ) M2(K6(REAL : ( ( ) ( V1() V30() V38() V39() V40() V44() ) set ) ) : ( ( ) ( ) set ) )) )) iff |.x : ( ( ) ( ext-real ) R_eal) .| : ( ( ) ( ext-real non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) = 0 : ( ( ) ( V1() V10() V11() V12() ext-real non positive non negative V38() V39() V40() V41() V42() V43() V44() V81() V82() ) M3( REAL : ( ( ) ( V1() V30() V38() V39() V40() V44() ) set ) , NAT : ( ( ) ( V38() V39() V40() V41() V42() V43() V44() ) M2(K6(REAL : ( ( ) ( V1() V30() V38() V39() V40() V44() ) set ) ) : ( ( ) ( ) set ) )) )) ) ;

theorem :: EXTREAL2:6
for x being ( ( ) ( ext-real ) R_eal) st |.x : ( ( ) ( ext-real ) R_eal) .| : ( ( ) ( ext-real non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) = - x : ( ( ) ( ext-real ) R_eal) : ( ( ) ( ext-real ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) & x : ( ( ) ( ext-real ) R_eal) <> 0 : ( ( ) ( V1() V10() V11() V12() ext-real non positive non negative V38() V39() V40() V41() V42() V43() V44() V81() V82() ) M3( REAL : ( ( ) ( V1() V30() V38() V39() V40() V44() ) set ) , NAT : ( ( ) ( V38() V39() V40() V41() V42() V43() V44() ) M2(K6(REAL : ( ( ) ( V1() V30() V38() V39() V40() V44() ) set ) ) : ( ( ) ( ) set ) )) )) holds
x : ( ( ) ( ext-real ) R_eal) < 0 : ( ( ) ( V1() V10() V11() V12() ext-real non positive non negative V38() V39() V40() V41() V42() V43() V44() V81() V82() ) M3( REAL : ( ( ) ( V1() V30() V38() V39() V40() V44() ) set ) , NAT : ( ( ) ( V38() V39() V40() V41() V42() V43() V44() ) M2(K6(REAL : ( ( ) ( V1() V30() V38() V39() V40() V44() ) set ) ) : ( ( ) ( ) set ) )) )) ;

theorem :: EXTREAL2:7
for x being ( ( ) ( ext-real ) R_eal) st x : ( ( ) ( ext-real ) R_eal) <= 0 : ( ( ) ( V1() V10() V11() V12() ext-real non positive non negative V38() V39() V40() V41() V42() V43() V44() V81() V82() ) M3( REAL : ( ( ) ( V1() V30() V38() V39() V40() V44() ) set ) , NAT : ( ( ) ( V38() V39() V40() V41() V42() V43() V44() ) M2(K6(REAL : ( ( ) ( V1() V30() V38() V39() V40() V44() ) set ) ) : ( ( ) ( ) set ) )) )) holds
|.x : ( ( ) ( ext-real ) R_eal) .| : ( ( ) ( ext-real non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) = - x : ( ( ) ( ext-real ) R_eal) : ( ( ) ( ext-real ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) ;

theorem :: EXTREAL2:8
for x, y being ( ( ) ( ext-real ) R_eal) holds |.(x : ( ( ) ( ext-real ) R_eal) * y : ( ( ) ( ext-real ) R_eal) ) : ( ( ) ( ext-real ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) .| : ( ( ) ( ext-real non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) = |.x : ( ( ) ( ext-real ) R_eal) .| : ( ( ) ( ext-real non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) * |.y : ( ( ) ( ext-real ) R_eal) .| : ( ( ) ( ext-real non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) : ( ( ) ( ext-real non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) ;

theorem :: EXTREAL2:9
for x being ( ( ) ( ext-real ) R_eal) holds
( - |.x : ( ( ) ( ext-real ) R_eal) .| : ( ( ) ( ext-real non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) : ( ( ) ( ext-real non positive ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) <= x : ( ( ) ( ext-real ) R_eal) & x : ( ( ) ( ext-real ) R_eal) <= |.x : ( ( ) ( ext-real ) R_eal) .| : ( ( ) ( ext-real non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) ) ;

theorem :: EXTREAL2:10
for x, y being ( ( ) ( ext-real ) R_eal) st |.x : ( ( ) ( ext-real ) R_eal) .| : ( ( ) ( ext-real non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) < y : ( ( ) ( ext-real ) R_eal) holds
( - y : ( ( ) ( ext-real ) R_eal) : ( ( ) ( ext-real ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) < x : ( ( ) ( ext-real ) R_eal) & x : ( ( ) ( ext-real ) R_eal) < y : ( ( ) ( ext-real ) R_eal) ) ;

theorem :: EXTREAL2:11
for y, x being ( ( ) ( ext-real ) R_eal) st - y : ( ( ) ( ext-real ) R_eal) : ( ( ) ( ext-real ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) < x : ( ( ) ( ext-real ) R_eal) & x : ( ( ) ( ext-real ) R_eal) < y : ( ( ) ( ext-real ) R_eal) holds
( 0 : ( ( ) ( V1() V10() V11() V12() ext-real non positive non negative V38() V39() V40() V41() V42() V43() V44() V81() V82() ) M3( REAL : ( ( ) ( V1() V30() V38() V39() V40() V44() ) set ) , NAT : ( ( ) ( V38() V39() V40() V41() V42() V43() V44() ) M2(K6(REAL : ( ( ) ( V1() V30() V38() V39() V40() V44() ) set ) ) : ( ( ) ( ) set ) )) )) < y : ( ( ) ( ext-real ) R_eal) & |.x : ( ( ) ( ext-real ) R_eal) .| : ( ( ) ( ext-real non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) < y : ( ( ) ( ext-real ) R_eal) ) ;

theorem :: EXTREAL2:12
for y, x being ( ( ) ( ext-real ) R_eal) holds
( ( - y : ( ( ) ( ext-real ) R_eal) : ( ( ) ( ext-real ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) <= x : ( ( ) ( ext-real ) R_eal) & x : ( ( ) ( ext-real ) R_eal) <= y : ( ( ) ( ext-real ) R_eal) ) iff |.x : ( ( ) ( ext-real ) R_eal) .| : ( ( ) ( ext-real non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) <= y : ( ( ) ( ext-real ) R_eal) ) ;

theorem :: EXTREAL2:13
for x, y being ( ( ) ( ext-real ) R_eal) holds |.(x : ( ( ) ( ext-real ) R_eal) + y : ( ( ) ( ext-real ) R_eal) ) : ( ( ) ( ext-real ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) .| : ( ( ) ( ext-real non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) <= |.x : ( ( ) ( ext-real ) R_eal) .| : ( ( ) ( ext-real non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) + |.y : ( ( ) ( ext-real ) R_eal) .| : ( ( ) ( ext-real non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) : ( ( ) ( ext-real non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) ;

theorem :: EXTREAL2:14
for x being ( ( ) ( ext-real ) R_eal) st -infty : ( ( ) ( V1() V12() ext-real non positive negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) < x : ( ( ) ( ext-real ) R_eal) & x : ( ( ) ( ext-real ) R_eal) < +infty : ( ( ) ( V1() V12() ext-real positive non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) & x : ( ( ) ( ext-real ) R_eal) <> 0 : ( ( ) ( V1() V10() V11() V12() ext-real non positive non negative V38() V39() V40() V41() V42() V43() V44() V81() V82() ) M3( REAL : ( ( ) ( V1() V30() V38() V39() V40() V44() ) set ) , NAT : ( ( ) ( V38() V39() V40() V41() V42() V43() V44() ) M2(K6(REAL : ( ( ) ( V1() V30() V38() V39() V40() V44() ) set ) ) : ( ( ) ( ) set ) )) )) holds
|.x : ( ( ) ( ext-real ) R_eal) .| : ( ( ) ( ext-real non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) * |.(1. : ( ( ) ( ext-real ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) / x : ( ( ) ( ext-real ) R_eal) ) : ( ( ) ( ext-real ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) .| : ( ( ) ( ext-real non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) : ( ( ) ( ext-real non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) = 1. : ( ( ) ( ext-real ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) ;

theorem :: EXTREAL2:15
for x being ( ( ) ( ext-real ) R_eal) st ( x : ( ( ) ( ext-real ) R_eal) = +infty : ( ( ) ( V1() V12() ext-real positive non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) or x : ( ( ) ( ext-real ) R_eal) = -infty : ( ( ) ( V1() V12() ext-real non positive negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) ) holds
|.x : ( ( ) ( ext-real ) R_eal) .| : ( ( ) ( ext-real non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) * |.(1. : ( ( ) ( ext-real ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) / x : ( ( ) ( ext-real ) R_eal) ) : ( ( ) ( ext-real ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) .| : ( ( ) ( ext-real non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) : ( ( ) ( ext-real non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) = 0 : ( ( ) ( V1() V10() V11() V12() ext-real non positive non negative V38() V39() V40() V41() V42() V43() V44() V81() V82() ) M3( REAL : ( ( ) ( V1() V30() V38() V39() V40() V44() ) set ) , NAT : ( ( ) ( V38() V39() V40() V41() V42() V43() V44() ) M2(K6(REAL : ( ( ) ( V1() V30() V38() V39() V40() V44() ) set ) ) : ( ( ) ( ) set ) )) )) ;

theorem :: EXTREAL2:16
for x being ( ( ) ( ext-real ) R_eal) st x : ( ( ) ( ext-real ) R_eal) <> 0 : ( ( ) ( V1() V10() V11() V12() ext-real non positive non negative V38() V39() V40() V41() V42() V43() V44() V81() V82() ) M3( REAL : ( ( ) ( V1() V30() V38() V39() V40() V44() ) set ) , NAT : ( ( ) ( V38() V39() V40() V41() V42() V43() V44() ) M2(K6(REAL : ( ( ) ( V1() V30() V38() V39() V40() V44() ) set ) ) : ( ( ) ( ) set ) )) )) holds
|.(1. : ( ( ) ( ext-real ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) / x : ( ( ) ( ext-real ) R_eal) ) : ( ( ) ( ext-real ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) .| : ( ( ) ( ext-real non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) = 1. : ( ( ) ( ext-real ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) / |.x : ( ( ) ( ext-real ) R_eal) .| : ( ( ) ( ext-real non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) : ( ( ) ( ext-real ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) ;

theorem :: EXTREAL2:17
for x, y being ( ( ) ( ext-real ) R_eal) st ( ( not x : ( ( ) ( ext-real ) R_eal) = -infty : ( ( ) ( V1() V12() ext-real non positive negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) & not x : ( ( ) ( ext-real ) R_eal) = +infty : ( ( ) ( V1() V12() ext-real positive non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) ) or ( not y : ( ( ) ( ext-real ) R_eal) = -infty : ( ( ) ( V1() V12() ext-real non positive negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) & not y : ( ( ) ( ext-real ) R_eal) = +infty : ( ( ) ( V1() V12() ext-real positive non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) ) ) & y : ( ( ) ( ext-real ) R_eal) <> 0 : ( ( ) ( V1() V10() V11() V12() ext-real non positive non negative V38() V39() V40() V41() V42() V43() V44() V81() V82() ) M3( REAL : ( ( ) ( V1() V30() V38() V39() V40() V44() ) set ) , NAT : ( ( ) ( V38() V39() V40() V41() V42() V43() V44() ) M2(K6(REAL : ( ( ) ( V1() V30() V38() V39() V40() V44() ) set ) ) : ( ( ) ( ) set ) )) )) holds
|.(x : ( ( ) ( ext-real ) R_eal) / y : ( ( ) ( ext-real ) R_eal) ) : ( ( ) ( ext-real ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) .| : ( ( ) ( ext-real non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) = |.x : ( ( ) ( ext-real ) R_eal) .| : ( ( ) ( ext-real non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) / |.y : ( ( ) ( ext-real ) R_eal) .| : ( ( ) ( ext-real non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) : ( ( ) ( ext-real non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) ;

theorem :: EXTREAL2:18
for x being ( ( ) ( ext-real ) R_eal) holds |.x : ( ( ) ( ext-real ) R_eal) .| : ( ( ) ( ext-real non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) = |.(- x : ( ( ) ( ext-real ) R_eal) ) : ( ( ) ( ext-real ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) .| : ( ( ) ( ext-real non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) ;

theorem :: EXTREAL2:19
( |.+infty : ( ( ) ( V1() V12() ext-real positive non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) .| : ( ( ) ( ext-real non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) = +infty : ( ( ) ( V1() V12() ext-real positive non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) & |.-infty : ( ( ) ( V1() V12() ext-real non positive negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) .| : ( ( ) ( ext-real non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) = +infty : ( ( ) ( V1() V12() ext-real positive non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) ) ;

theorem :: EXTREAL2:20
for x, y being ( ( ) ( ext-real ) R_eal) st ( x : ( ( ) ( ext-real ) R_eal) is ( ( ) ( V11() V12() ext-real ) Real) or y : ( ( ) ( ext-real ) R_eal) is ( ( ) ( V11() V12() ext-real ) Real) ) holds
|.x : ( ( ) ( ext-real ) R_eal) .| : ( ( ) ( ext-real non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) - |.y : ( ( ) ( ext-real ) R_eal) .| : ( ( ) ( ext-real non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) : ( ( ) ( ext-real ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) <= |.(x : ( ( ) ( ext-real ) R_eal) - y : ( ( ) ( ext-real ) R_eal) ) : ( ( ) ( ext-real ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) .| : ( ( ) ( ext-real non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) ;

theorem :: EXTREAL2:21
for x, y being ( ( ) ( ext-real ) R_eal) holds |.(x : ( ( ) ( ext-real ) R_eal) - y : ( ( ) ( ext-real ) R_eal) ) : ( ( ) ( ext-real ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) .| : ( ( ) ( ext-real non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) <= |.x : ( ( ) ( ext-real ) R_eal) .| : ( ( ) ( ext-real non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) + |.y : ( ( ) ( ext-real ) R_eal) .| : ( ( ) ( ext-real non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) : ( ( ) ( ext-real non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) ;

theorem :: EXTREAL2:22
canceled;

theorem :: EXTREAL2:23
for x, z, y, w being ( ( ) ( ext-real ) R_eal) st |.x : ( ( ) ( ext-real ) R_eal) .| : ( ( ) ( ext-real non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) <= z : ( ( ) ( ext-real ) R_eal) & |.y : ( ( ) ( ext-real ) R_eal) .| : ( ( ) ( ext-real non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) <= w : ( ( ) ( ext-real ) R_eal) holds
|.(x : ( ( ) ( ext-real ) R_eal) + y : ( ( ) ( ext-real ) R_eal) ) : ( ( ) ( ext-real ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) .| : ( ( ) ( ext-real non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) <= z : ( ( ) ( ext-real ) R_eal) + w : ( ( ) ( ext-real ) R_eal) : ( ( ) ( ext-real ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) ;

theorem :: EXTREAL2:24
for x, y being ( ( ) ( ext-real ) R_eal) st ( x : ( ( ) ( ext-real ) R_eal) is ( ( ) ( V11() V12() ext-real ) Real) or y : ( ( ) ( ext-real ) R_eal) is ( ( ) ( V11() V12() ext-real ) Real) ) holds
|.(|.x : ( ( ) ( ext-real ) R_eal) .| : ( ( ) ( ext-real non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) - |.y : ( ( ) ( ext-real ) R_eal) .| : ( ( ) ( ext-real non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) ) : ( ( ) ( ext-real ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) .| : ( ( ) ( ext-real non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) <= |.(x : ( ( ) ( ext-real ) R_eal) - y : ( ( ) ( ext-real ) R_eal) ) : ( ( ) ( ext-real ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) .| : ( ( ) ( ext-real non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) ;

theorem :: EXTREAL2:25
for x, y being ( ( ) ( ext-real ) R_eal) st 0 : ( ( ) ( V1() V10() V11() V12() ext-real non positive non negative V38() V39() V40() V41() V42() V43() V44() V81() V82() ) M3( REAL : ( ( ) ( V1() V30() V38() V39() V40() V44() ) set ) , NAT : ( ( ) ( V38() V39() V40() V41() V42() V43() V44() ) M2(K6(REAL : ( ( ) ( V1() V30() V38() V39() V40() V44() ) set ) ) : ( ( ) ( ) set ) )) )) <= x : ( ( ) ( ext-real ) R_eal) * y : ( ( ) ( ext-real ) R_eal) : ( ( ) ( ext-real ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) holds
|.(x : ( ( ) ( ext-real ) R_eal) + y : ( ( ) ( ext-real ) R_eal) ) : ( ( ) ( ext-real ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) .| : ( ( ) ( ext-real non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) = |.x : ( ( ) ( ext-real ) R_eal) .| : ( ( ) ( ext-real non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) + |.y : ( ( ) ( ext-real ) R_eal) .| : ( ( ) ( ext-real non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) : ( ( ) ( ext-real non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) ;

begin

theorem :: EXTREAL2:26
for x, y being ( ( ) ( ext-real ) R_eal) st x : ( ( ) ( ext-real ) R_eal) <> +infty : ( ( ) ( V1() V12() ext-real positive non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) & y : ( ( ) ( ext-real ) R_eal) <> +infty : ( ( ) ( V1() V12() ext-real positive non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) & not ( x : ( ( ) ( ext-real ) R_eal) = +infty : ( ( ) ( V1() V12() ext-real positive non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) & y : ( ( ) ( ext-real ) R_eal) = +infty : ( ( ) ( V1() V12() ext-real positive non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) ) & not ( x : ( ( ) ( ext-real ) R_eal) = -infty : ( ( ) ( V1() V12() ext-real non positive negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) & y : ( ( ) ( ext-real ) R_eal) = -infty : ( ( ) ( V1() V12() ext-real non positive negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) ) holds
min (x : ( ( ) ( ext-real ) R_eal) ,y : ( ( ) ( ext-real ) R_eal) ) : ( ( ) ( ext-real ) set ) = ((x : ( ( ) ( ext-real ) R_eal) + y : ( ( ) ( ext-real ) R_eal) ) : ( ( ) ( ext-real ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) - |.(x : ( ( ) ( ext-real ) R_eal) - y : ( ( ) ( ext-real ) R_eal) ) : ( ( ) ( ext-real ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) .| : ( ( ) ( ext-real non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) ) : ( ( ) ( ext-real ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) / (R_EAL 2 : ( ( ) ( V1() V10() V11() V12() ext-real positive non negative V38() V39() V40() V41() V42() V43() V81() V82() ) M3( REAL : ( ( ) ( V1() V30() V38() V39() V40() V44() ) set ) , NAT : ( ( ) ( V38() V39() V40() V41() V42() V43() V44() ) M2(K6(REAL : ( ( ) ( V1() V30() V38() V39() V40() V44() ) set ) ) : ( ( ) ( ) set ) )) )) ) : ( ( ) ( ext-real ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) : ( ( ) ( ext-real ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) ;

theorem :: EXTREAL2:27
for x, y being ( ( ) ( ext-real ) R_eal) st x : ( ( ) ( ext-real ) R_eal) <> -infty : ( ( ) ( V1() V12() ext-real non positive negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) & y : ( ( ) ( ext-real ) R_eal) <> -infty : ( ( ) ( V1() V12() ext-real non positive negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) & not ( x : ( ( ) ( ext-real ) R_eal) = +infty : ( ( ) ( V1() V12() ext-real positive non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) & y : ( ( ) ( ext-real ) R_eal) = +infty : ( ( ) ( V1() V12() ext-real positive non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) ) & not ( x : ( ( ) ( ext-real ) R_eal) = -infty : ( ( ) ( V1() V12() ext-real non positive negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) & y : ( ( ) ( ext-real ) R_eal) = -infty : ( ( ) ( V1() V12() ext-real non positive negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) ) holds
max (x : ( ( ) ( ext-real ) R_eal) ,y : ( ( ) ( ext-real ) R_eal) ) : ( ( ) ( ext-real ) set ) = ((x : ( ( ) ( ext-real ) R_eal) + y : ( ( ) ( ext-real ) R_eal) ) : ( ( ) ( ext-real ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) + |.(x : ( ( ) ( ext-real ) R_eal) - y : ( ( ) ( ext-real ) R_eal) ) : ( ( ) ( ext-real ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) .| : ( ( ) ( ext-real non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) ) : ( ( ) ( ext-real ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) / (R_EAL 2 : ( ( ) ( V1() V10() V11() V12() ext-real positive non negative V38() V39() V40() V41() V42() V43() V81() V82() ) M3( REAL : ( ( ) ( V1() V30() V38() V39() V40() V44() ) set ) , NAT : ( ( ) ( V38() V39() V40() V41() V42() V43() V44() ) M2(K6(REAL : ( ( ) ( V1() V30() V38() V39() V40() V44() ) set ) ) : ( ( ) ( ) set ) )) )) ) : ( ( ) ( ext-real ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) : ( ( ) ( ext-real ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) ;

definition
let x, y be ( ( ) ( ext-real ) R_eal) ;
:: original: max
redefine func max (x,y) -> ( ( ) ( ext-real ) R_eal) ;
:: original: min
redefine func min (x,y) -> ( ( ) ( ext-real ) R_eal) ;
end;

theorem :: EXTREAL2:28
for x, y being ( ( ) ( ext-real ) R_eal) holds (min (x : ( ( ) ( ext-real ) R_eal) ,y : ( ( ) ( ext-real ) R_eal) )) : ( ( ) ( ext-real ) R_eal) + (max (x : ( ( ) ( ext-real ) R_eal) ,y : ( ( ) ( ext-real ) R_eal) )) : ( ( ) ( ext-real ) R_eal) : ( ( ) ( ext-real ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) = x : ( ( ) ( ext-real ) R_eal) + y : ( ( ) ( ext-real ) R_eal) : ( ( ) ( ext-real ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) ;

begin

theorem :: EXTREAL2:29
for x being ( ( ) ( ext-real ) R_eal) holds
( not |.x : ( ( ) ( ext-real ) R_eal) .| : ( ( ) ( ext-real non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) = +infty : ( ( ) ( V1() V12() ext-real positive non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) or x : ( ( ) ( ext-real ) R_eal) = +infty : ( ( ) ( V1() V12() ext-real positive non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) or x : ( ( ) ( ext-real ) R_eal) = -infty : ( ( ) ( V1() V12() ext-real non positive negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) ) ;

theorem :: EXTREAL2:30
for x being ( ( ) ( ext-real ) R_eal) holds
( |.x : ( ( ) ( ext-real ) R_eal) .| : ( ( ) ( ext-real non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) < +infty : ( ( ) ( V1() V12() ext-real positive non negative ) M2( ExtREAL : ( ( ) ( V1() V39() ) set ) )) iff x : ( ( ) ( ext-real ) R_eal) in REAL : ( ( ) ( V1() V30() V38() V39() V40() V44() ) set ) ) ;