consider f being BinOp of REAL such that
A1:
for x, y being Real holds f . x,y = min x,y
from BINOP_1:sch 4();
let M be non empty Moore-SM_Final of [:REAL ,REAL :], succ REAL ; :: thesis: ( M is calculating_type & the carrier of M = succ REAL & the FinalS of M = REAL & the InitS of M = REAL & the OFun of M = id the carrier of M & ( for x, y being Real st x < y holds
the Tran of M . [the InitS of M,[x,y]] = x ) & ( for x, y being Real st x >= y holds
the Tran of M . [the InitS of M,[x,y]] = y ) implies for x, y being Element of REAL holds min x,y is_result_of [x,y],M )
assume A2:
( M is calculating_type & the carrier of M = succ REAL & the FinalS of M = REAL & the InitS of M = REAL & the OFun of M = id the carrier of M )
; :: thesis: ( ex x, y being Real st
( x < y & not the Tran of M . [the InitS of M,[x,y]] = x ) or ex x, y being Real st
( x >= y & not the Tran of M . [the InitS of M,[x,y]] = y ) or for x, y being Element of REAL holds min x,y is_result_of [x,y],M )
assume A3:
( ( for x, y being Real st x < y holds
the Tran of M . [the InitS of M,[x,y]] = x ) & ( for x, y being Real st x >= y holds
the Tran of M . [the InitS of M,[x,y]] = y ) )
; :: thesis: for x, y being Element of REAL holds min x,y is_result_of [x,y],M
let x, y be Real; :: thesis: min x,y is_result_of [x,y],M
now let x,
y be
Real;
:: thesis: the Tran of M . [the InitS of M,[x,y]] = f . x,y
( (
x < y implies the
Tran of
M . [the InitS of M,[x,y]] = x ) & (
x >= y implies the
Tran of
M . [the InitS of M,[x,y]] = y ) )
by A3;
then
the
Tran of
M . [the InitS of M,[x,y]] = min x,
y
by XXREAL_0:def 9;
hence
the
Tran of
M . [the InitS of M,[x,y]] = f . x,
y
by A1;
:: thesis: verum end;
then
f . x,y is_result_of [x,y],M
by A2, Th22;
hence
min x,y is_result_of [x,y],M
by A1; :: thesis: verum