let A be non empty closed_interval Subset of REAL; for r1, r2 being Real
for f being Function of REAL,REAL st f is_integrable_on A & f | A is bounded holds
( min ((AffineMap (0,r1)),(r2 (#) f)) is_integrable_on A & (min ((AffineMap (0,r1)),(r2 (#) f))) | A is bounded )
let r1, r2 be Real; for f being Function of REAL,REAL st f is_integrable_on A & f | A is bounded holds
( min ((AffineMap (0,r1)),(r2 (#) f)) is_integrable_on A & (min ((AffineMap (0,r1)),(r2 (#) f))) | A is bounded )
let f be Function of REAL,REAL; ( f is_integrable_on A & f | A is bounded implies ( min ((AffineMap (0,r1)),(r2 (#) f)) is_integrable_on A & (min ((AffineMap (0,r1)),(r2 (#) f))) | A is bounded ) )
assume that
A2:
f is_integrable_on A
and
A3:
f | A is bounded
; ( min ((AffineMap (0,r1)),(r2 (#) f)) is_integrable_on A & (min ((AffineMap (0,r1)),(r2 (#) f))) | A is bounded )
A c= REAL
;
then Df:
A c= dom f
by FUNCT_2:def 1;
A c= REAL
;
then B21:
A c= dom (AffineMap (0,r1))
by FUNCT_2:def 1;
set F3 = AffineMap (0,r1);
reconsider f = f, F3 = AffineMap (0,r1) as PartFunc of REAL,REAL ;
C1:
F3 | A is continuous
;
A23:
( f is_integrable_on A & f | A is bounded )
by A2, A3;
reconsider f = f, F3 = F3 as Function of REAL,REAL ;
( F3 is_integrable_on A & F3 | A is bounded & r2 (#) f is_integrable_on A & (r2 (#) f) | A is bounded )
by INTEGRA6:9, Df, A23, RFUNCT_1:80, C1, INTEGRA5:10, INTEGRA5:11, B21;
hence
( min ((AffineMap (0,r1)),(r2 (#) f)) is_integrable_on A & (min ((AffineMap (0,r1)),(r2 (#) f))) | A is bounded )
by Th12; verum