Metamath Proof Explorer


Theorem supminfxrrnmpt

Description: The indexed supremum of a set of reals is the negation of the indexed infimum of that set's image under negation. (Contributed by Glauco Siliprandi, 2-Jan-2022)

Ref Expression
Hypotheses supminfxrrnmpt.x
|- F/ x ph
supminfxrrnmpt.b
|- ( ( ph /\ x e. A ) -> B e. RR* )
Assertion supminfxrrnmpt
|- ( ph -> sup ( ran ( x e. A |-> B ) , RR* , < ) = -e inf ( ran ( x e. A |-> -e B ) , RR* , < ) )

Proof

Step Hyp Ref Expression
1 supminfxrrnmpt.x
 |-  F/ x ph
2 supminfxrrnmpt.b
 |-  ( ( ph /\ x e. A ) -> B e. RR* )
3 eqid
 |-  ( x e. A |-> B ) = ( x e. A |-> B )
4 1 3 2 rnmptssd
 |-  ( ph -> ran ( x e. A |-> B ) C_ RR* )
5 4 supminfxr2
 |-  ( ph -> sup ( ran ( x e. A |-> B ) , RR* , < ) = -e inf ( { y e. RR* | -e y e. ran ( x e. A |-> B ) } , RR* , < ) )
6 xnegex
 |-  -e y e. _V
7 3 elrnmpt
 |-  ( -e y e. _V -> ( -e y e. ran ( x e. A |-> B ) <-> E. x e. A -e y = B ) )
8 6 7 ax-mp
 |-  ( -e y e. ran ( x e. A |-> B ) <-> E. x e. A -e y = B )
9 8 biimpi
 |-  ( -e y e. ran ( x e. A |-> B ) -> E. x e. A -e y = B )
10 eqid
 |-  ( x e. A |-> -e B ) = ( x e. A |-> -e B )
11 xnegneg
 |-  ( y e. RR* -> -e -e y = y )
12 11 eqcomd
 |-  ( y e. RR* -> y = -e -e y )
13 12 adantr
 |-  ( ( y e. RR* /\ -e y = B ) -> y = -e -e y )
14 xnegeq
 |-  ( -e y = B -> -e -e y = -e B )
15 14 adantl
 |-  ( ( y e. RR* /\ -e y = B ) -> -e -e y = -e B )
16 13 15 eqtrd
 |-  ( ( y e. RR* /\ -e y = B ) -> y = -e B )
17 16 ex
 |-  ( y e. RR* -> ( -e y = B -> y = -e B ) )
18 17 reximdv
 |-  ( y e. RR* -> ( E. x e. A -e y = B -> E. x e. A y = -e B ) )
19 18 imp
 |-  ( ( y e. RR* /\ E. x e. A -e y = B ) -> E. x e. A y = -e B )
20 simpl
 |-  ( ( y e. RR* /\ E. x e. A -e y = B ) -> y e. RR* )
21 10 19 20 elrnmptd
 |-  ( ( y e. RR* /\ E. x e. A -e y = B ) -> y e. ran ( x e. A |-> -e B ) )
22 9 21 sylan2
 |-  ( ( y e. RR* /\ -e y e. ran ( x e. A |-> B ) ) -> y e. ran ( x e. A |-> -e B ) )
23 22 ex
 |-  ( y e. RR* -> ( -e y e. ran ( x e. A |-> B ) -> y e. ran ( x e. A |-> -e B ) ) )
24 23 rgen
 |-  A. y e. RR* ( -e y e. ran ( x e. A |-> B ) -> y e. ran ( x e. A |-> -e B ) )
25 rabss
 |-  ( { y e. RR* | -e y e. ran ( x e. A |-> B ) } C_ ran ( x e. A |-> -e B ) <-> A. y e. RR* ( -e y e. ran ( x e. A |-> B ) -> y e. ran ( x e. A |-> -e B ) ) )
26 25 biimpri
 |-  ( A. y e. RR* ( -e y e. ran ( x e. A |-> B ) -> y e. ran ( x e. A |-> -e B ) ) -> { y e. RR* | -e y e. ran ( x e. A |-> B ) } C_ ran ( x e. A |-> -e B ) )
27 24 26 ax-mp
 |-  { y e. RR* | -e y e. ran ( x e. A |-> B ) } C_ ran ( x e. A |-> -e B )
28 27 a1i
 |-  ( ph -> { y e. RR* | -e y e. ran ( x e. A |-> B ) } C_ ran ( x e. A |-> -e B ) )
29 nfcv
 |-  F/_ x -e y
30 nfmpt1
 |-  F/_ x ( x e. A |-> B )
31 30 nfrn
 |-  F/_ x ran ( x e. A |-> B )
32 29 31 nfel
 |-  F/ x -e y e. ran ( x e. A |-> B )
33 nfcv
 |-  F/_ x RR*
34 32 33 nfrabw
 |-  F/_ x { y e. RR* | -e y e. ran ( x e. A |-> B ) }
35 xnegeq
 |-  ( y = -e B -> -e y = -e -e B )
36 35 eleq1d
 |-  ( y = -e B -> ( -e y e. ran ( x e. A |-> B ) <-> -e -e B e. ran ( x e. A |-> B ) ) )
37 2 xnegcld
 |-  ( ( ph /\ x e. A ) -> -e B e. RR* )
38 xnegneg
 |-  ( B e. RR* -> -e -e B = B )
39 2 38 syl
 |-  ( ( ph /\ x e. A ) -> -e -e B = B )
40 simpr
 |-  ( ( ph /\ x e. A ) -> x e. A )
41 3 40 2 elrnmpt1d
 |-  ( ( ph /\ x e. A ) -> B e. ran ( x e. A |-> B ) )
42 39 41 eqeltrd
 |-  ( ( ph /\ x e. A ) -> -e -e B e. ran ( x e. A |-> B ) )
43 36 37 42 elrabd
 |-  ( ( ph /\ x e. A ) -> -e B e. { y e. RR* | -e y e. ran ( x e. A |-> B ) } )
44 1 34 10 43 rnmptssdf
 |-  ( ph -> ran ( x e. A |-> -e B ) C_ { y e. RR* | -e y e. ran ( x e. A |-> B ) } )
45 28 44 eqssd
 |-  ( ph -> { y e. RR* | -e y e. ran ( x e. A |-> B ) } = ran ( x e. A |-> -e B ) )
46 45 infeq1d
 |-  ( ph -> inf ( { y e. RR* | -e y e. ran ( x e. A |-> B ) } , RR* , < ) = inf ( ran ( x e. A |-> -e B ) , RR* , < ) )
47 46 xnegeqd
 |-  ( ph -> -e inf ( { y e. RR* | -e y e. ran ( x e. A |-> B ) } , RR* , < ) = -e inf ( ran ( x e. A |-> -e B ) , RR* , < ) )
48 5 47 eqtrd
 |-  ( ph -> sup ( ran ( x e. A |-> B ) , RR* , < ) = -e inf ( ran ( x e. A |-> -e B ) , RR* , < ) )