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Theorem ivthreinc 14881
Description: Restating the intermediate value theorem. Given a hypothesis stating the intermediate value theorem (in a strong form which is not provable given our axioms alone), provide a conclusion similar to the theorem as stated in the Metamath Proof Explorer (which is also similar to how we state the theorem for a strictly monotonic function at ivthinc 14879). Being able to have a hypothesis stating the intermediate value theorem will be helpful when it comes time to show that it implies a constructive taboo. This version of the theorem requires that the function  F is continuous on the entire real line, not just  ( A [,] B ) which may be an unnecessary condition but which is sufficient for the way we want to use it. (Contributed by Jim Kingdon, 7-Jul-2025.)
Hypotheses
Ref Expression
ivthreinc.1  |-  ( ph  ->  A  e.  RR )
ivthreinc.2  |-  ( ph  ->  B  e.  RR )
ivthreinc.3  |-  ( ph  ->  U  e.  RR )
ivthreinc.4  |-  ( ph  ->  A  <  B )
ivthreinc.7  |-  ( ph  ->  F  e.  ( RR
-cn-> RR ) )
ivthreinc.9  |-  ( ph  ->  ( ( F `  A )  <  U  /\  U  <  ( F `
 B ) ) )
ivthreinc.i  |-  ( ph  ->  A. f ( f  e.  ( RR -cn-> RR )  ->  A. a  e.  RR  A. b  e.  RR  ( ( a  <  b  /\  (
f `  a )  <  0  /\  0  < 
( f `  b
) )  ->  E. x  e.  RR  ( a  < 
x  /\  x  <  b  /\  ( f `  x )  =  0 ) ) ) )
Assertion
Ref Expression
ivthreinc  |-  ( ph  ->  E. c  e.  ( A (,) B ) ( F `  c
)  =  U )
Distinct variable groups:    A, a, b, x    A, c, x    B, b, x    B, c    F, a, b, f, x    F, c    U, a, b, f, x    U, c    ph, x
Allowed substitution hints:    ph( f, a, b, c)    A( f)    B( f, a)

Proof of Theorem ivthreinc
Dummy variable  r is distinct from all other variables.
StepHypRef Expression
1 ivthreinc.4 . . . 4  |-  ( ph  ->  A  <  B )
2 eqid 2196 . . . . . 6  |-  ( r  e.  RR  |->  ( ( F `  r )  -  U ) )  =  ( r  e.  RR  |->  ( ( F `
 r )  -  U ) )
3 fveq2 5558 . . . . . . 7  |-  ( r  =  A  ->  ( F `  r )  =  ( F `  A ) )
43oveq1d 5937 . . . . . 6  |-  ( r  =  A  ->  (
( F `  r
)  -  U )  =  ( ( F `
 A )  -  U ) )
5 ivthreinc.1 . . . . . 6  |-  ( ph  ->  A  e.  RR )
6 ivthreinc.7 . . . . . . . . 9  |-  ( ph  ->  F  e.  ( RR
-cn-> RR ) )
7 cncff 14813 . . . . . . . . 9  |-  ( F  e.  ( RR -cn-> RR )  ->  F : RR
--> RR )
86, 7syl 14 . . . . . . . 8  |-  ( ph  ->  F : RR --> RR )
98, 5ffvelcdmd 5698 . . . . . . 7  |-  ( ph  ->  ( F `  A
)  e.  RR )
10 ivthreinc.3 . . . . . . 7  |-  ( ph  ->  U  e.  RR )
119, 10resubcld 8407 . . . . . 6  |-  ( ph  ->  ( ( F `  A )  -  U
)  e.  RR )
122, 4, 5, 11fvmptd3 5655 . . . . 5  |-  ( ph  ->  ( ( r  e.  RR  |->  ( ( F `
 r )  -  U ) ) `  A )  =  ( ( F `  A
)  -  U ) )
13 ivthreinc.9 . . . . . . 7  |-  ( ph  ->  ( ( F `  A )  <  U  /\  U  <  ( F `
 B ) ) )
1413simpld 112 . . . . . 6  |-  ( ph  ->  ( F `  A
)  <  U )
159, 10sublt0d 8597 . . . . . 6  |-  ( ph  ->  ( ( ( F `
 A )  -  U )  <  0  <->  ( F `  A )  <  U ) )
1614, 15mpbird 167 . . . . 5  |-  ( ph  ->  ( ( F `  A )  -  U
)  <  0 )
1712, 16eqbrtrd 4055 . . . 4  |-  ( ph  ->  ( ( r  e.  RR  |->  ( ( F `
 r )  -  U ) ) `  A )  <  0
)
1813simprd 114 . . . . . 6  |-  ( ph  ->  U  <  ( F `
 B ) )
19 ivthreinc.2 . . . . . . . 8  |-  ( ph  ->  B  e.  RR )
208, 19ffvelcdmd 5698 . . . . . . 7  |-  ( ph  ->  ( F `  B
)  e.  RR )
2110, 20posdifd 8559 . . . . . 6  |-  ( ph  ->  ( U  <  ( F `  B )  <->  0  <  ( ( F `
 B )  -  U ) ) )
2218, 21mpbid 147 . . . . 5  |-  ( ph  ->  0  <  ( ( F `  B )  -  U ) )
23 fveq2 5558 . . . . . . 7  |-  ( r  =  B  ->  ( F `  r )  =  ( F `  B ) )
2423oveq1d 5937 . . . . . 6  |-  ( r  =  B  ->  (
( F `  r
)  -  U )  =  ( ( F `
 B )  -  U ) )
2520, 10resubcld 8407 . . . . . 6  |-  ( ph  ->  ( ( F `  B )  -  U
)  e.  RR )
262, 24, 19, 25fvmptd3 5655 . . . . 5  |-  ( ph  ->  ( ( r  e.  RR  |->  ( ( F `
 r )  -  U ) ) `  B )  =  ( ( F `  B
)  -  U ) )
2722, 26breqtrrd 4061 . . . 4  |-  ( ph  ->  0  <  ( ( r  e.  RR  |->  ( ( F `  r
)  -  U ) ) `  B ) )
281, 17, 273jca 1179 . . 3  |-  ( ph  ->  ( A  <  B  /\  ( ( r  e.  RR  |->  ( ( F `
 r )  -  U ) ) `  A )  <  0  /\  0  <  ( ( r  e.  RR  |->  ( ( F `  r
)  -  U ) ) `  B ) ) )
29 breq2 4037 . . . . . 6  |-  ( b  =  B  ->  ( A  <  b  <->  A  <  B ) )
30 fveq2 5558 . . . . . . 7  |-  ( b  =  B  ->  (
( r  e.  RR  |->  ( ( F `  r )  -  U
) ) `  b
)  =  ( ( r  e.  RR  |->  ( ( F `  r
)  -  U ) ) `  B ) )
3130breq2d 4045 . . . . . 6  |-  ( b  =  B  ->  (
0  <  ( (
r  e.  RR  |->  ( ( F `  r
)  -  U ) ) `  b )  <->  0  <  ( ( r  e.  RR  |->  ( ( F `  r
)  -  U ) ) `  B ) ) )
3229, 313anbi13d 1325 . . . . 5  |-  ( b  =  B  ->  (
( A  <  b  /\  ( ( r  e.  RR  |->  ( ( F `
 r )  -  U ) ) `  A )  <  0  /\  0  <  ( ( r  e.  RR  |->  ( ( F `  r
)  -  U ) ) `  b ) )  <->  ( A  < 
B  /\  ( (
r  e.  RR  |->  ( ( F `  r
)  -  U ) ) `  A )  <  0  /\  0  <  ( ( r  e.  RR  |->  ( ( F `
 r )  -  U ) ) `  B ) ) ) )
33 breq2 4037 . . . . . . 7  |-  ( b  =  B  ->  (
x  <  b  <->  x  <  B ) )
34333anbi2d 1328 . . . . . 6  |-  ( b  =  B  ->  (
( A  <  x  /\  x  <  b  /\  ( ( r  e.  RR  |->  ( ( F `
 r )  -  U ) ) `  x )  =  0 )  <->  ( A  < 
x  /\  x  <  B  /\  ( ( r  e.  RR  |->  ( ( F `  r )  -  U ) ) `
 x )  =  0 ) ) )
3534rexbidv 2498 . . . . 5  |-  ( b  =  B  ->  ( E. x  e.  RR  ( A  <  x  /\  x  <  b  /\  (
( r  e.  RR  |->  ( ( F `  r )  -  U
) ) `  x
)  =  0 )  <->  E. x  e.  RR  ( A  <  x  /\  x  <  B  /\  (
( r  e.  RR  |->  ( ( F `  r )  -  U
) ) `  x
)  =  0 ) ) )
3632, 35imbi12d 234 . . . 4  |-  ( b  =  B  ->  (
( ( A  < 
b  /\  ( (
r  e.  RR  |->  ( ( F `  r
)  -  U ) ) `  A )  <  0  /\  0  <  ( ( r  e.  RR  |->  ( ( F `
 r )  -  U ) ) `  b ) )  ->  E. x  e.  RR  ( A  <  x  /\  x  <  b  /\  (
( r  e.  RR  |->  ( ( F `  r )  -  U
) ) `  x
)  =  0 ) )  <->  ( ( A  <  B  /\  (
( r  e.  RR  |->  ( ( F `  r )  -  U
) ) `  A
)  <  0  /\  0  <  ( ( r  e.  RR  |->  ( ( F `  r )  -  U ) ) `
 B ) )  ->  E. x  e.  RR  ( A  <  x  /\  x  <  B  /\  (
( r  e.  RR  |->  ( ( F `  r )  -  U
) ) `  x
)  =  0 ) ) ) )
37 breq1 4036 . . . . . . . 8  |-  ( a  =  A  ->  (
a  <  b  <->  A  <  b ) )
38 fveq2 5558 . . . . . . . . 9  |-  ( a  =  A  ->  (
( r  e.  RR  |->  ( ( F `  r )  -  U
) ) `  a
)  =  ( ( r  e.  RR  |->  ( ( F `  r
)  -  U ) ) `  A ) )
3938breq1d 4043 . . . . . . . 8  |-  ( a  =  A  ->  (
( ( r  e.  RR  |->  ( ( F `
 r )  -  U ) ) `  a )  <  0  <->  ( ( r  e.  RR  |->  ( ( F `  r )  -  U
) ) `  A
)  <  0 ) )
4037, 393anbi12d 1324 . . . . . . 7  |-  ( a  =  A  ->  (
( a  <  b  /\  ( ( r  e.  RR  |->  ( ( F `
 r )  -  U ) ) `  a )  <  0  /\  0  <  ( ( r  e.  RR  |->  ( ( F `  r
)  -  U ) ) `  b ) )  <->  ( A  < 
b  /\  ( (
r  e.  RR  |->  ( ( F `  r
)  -  U ) ) `  A )  <  0  /\  0  <  ( ( r  e.  RR  |->  ( ( F `
 r )  -  U ) ) `  b ) ) ) )
41 breq1 4036 . . . . . . . . 9  |-  ( a  =  A  ->  (
a  <  x  <->  A  <  x ) )
42413anbi1d 1327 . . . . . . . 8  |-  ( a  =  A  ->  (
( a  <  x  /\  x  <  b  /\  ( ( r  e.  RR  |->  ( ( F `
 r )  -  U ) ) `  x )  =  0 )  <->  ( A  < 
x  /\  x  <  b  /\  ( ( r  e.  RR  |->  ( ( F `  r )  -  U ) ) `
 x )  =  0 ) ) )
4342rexbidv 2498 . . . . . . 7  |-  ( a  =  A  ->  ( E. x  e.  RR  ( a  <  x  /\  x  <  b  /\  ( ( r  e.  RR  |->  ( ( F `
 r )  -  U ) ) `  x )  =  0 )  <->  E. x  e.  RR  ( A  <  x  /\  x  <  b  /\  (
( r  e.  RR  |->  ( ( F `  r )  -  U
) ) `  x
)  =  0 ) ) )
4440, 43imbi12d 234 . . . . . 6  |-  ( a  =  A  ->  (
( ( a  < 
b  /\  ( (
r  e.  RR  |->  ( ( F `  r
)  -  U ) ) `  a )  <  0  /\  0  <  ( ( r  e.  RR  |->  ( ( F `
 r )  -  U ) ) `  b ) )  ->  E. x  e.  RR  ( a  <  x  /\  x  <  b  /\  ( ( r  e.  RR  |->  ( ( F `
 r )  -  U ) ) `  x )  =  0 ) )  <->  ( ( A  <  b  /\  (
( r  e.  RR  |->  ( ( F `  r )  -  U
) ) `  A
)  <  0  /\  0  <  ( ( r  e.  RR  |->  ( ( F `  r )  -  U ) ) `
 b ) )  ->  E. x  e.  RR  ( A  <  x  /\  x  <  b  /\  (
( r  e.  RR  |->  ( ( F `  r )  -  U
) ) `  x
)  =  0 ) ) ) )
4544ralbidv 2497 . . . . 5  |-  ( a  =  A  ->  ( A. b  e.  RR  ( ( a  < 
b  /\  ( (
r  e.  RR  |->  ( ( F `  r
)  -  U ) ) `  a )  <  0  /\  0  <  ( ( r  e.  RR  |->  ( ( F `
 r )  -  U ) ) `  b ) )  ->  E. x  e.  RR  ( a  <  x  /\  x  <  b  /\  ( ( r  e.  RR  |->  ( ( F `
 r )  -  U ) ) `  x )  =  0 ) )  <->  A. b  e.  RR  ( ( A  <  b  /\  (
( r  e.  RR  |->  ( ( F `  r )  -  U
) ) `  A
)  <  0  /\  0  <  ( ( r  e.  RR  |->  ( ( F `  r )  -  U ) ) `
 b ) )  ->  E. x  e.  RR  ( A  <  x  /\  x  <  b  /\  (
( r  e.  RR  |->  ( ( F `  r )  -  U
) ) `  x
)  =  0 ) ) ) )
468ffvelcdmda 5697 . . . . . . . . 9  |-  ( (
ph  /\  r  e.  RR )  ->  ( F `
 r )  e.  RR )
4710adantr 276 . . . . . . . . 9  |-  ( (
ph  /\  r  e.  RR )  ->  U  e.  RR )
4846, 47resubcld 8407 . . . . . . . 8  |-  ( (
ph  /\  r  e.  RR )  ->  ( ( F `  r )  -  U )  e.  RR )
4948fmpttd 5717 . . . . . . 7  |-  ( ph  ->  ( r  e.  RR  |->  ( ( F `  r )  -  U
) ) : RR --> RR )
50 ax-resscn 7971 . . . . . . . . 9  |-  RR  C_  CC
5150a1i 9 . . . . . . . 8  |-  ( ph  ->  RR  C_  CC )
528feqmptd 5614 . . . . . . . . . 10  |-  ( ph  ->  F  =  ( r  e.  RR  |->  ( F `
 r ) ) )
53 ssid 3203 . . . . . . . . . . . 12  |-  CC  C_  CC
54 cncfss 14819 . . . . . . . . . . . 12  |-  ( ( RR  C_  CC  /\  CC  C_  CC )  ->  ( RR -cn-> RR )  C_  ( RR -cn-> CC ) )
5550, 53, 54mp2an 426 . . . . . . . . . . 11  |-  ( RR
-cn-> RR )  C_  ( RR -cn-> CC )
5655, 6sselid 3181 . . . . . . . . . 10  |-  ( ph  ->  F  e.  ( RR
-cn-> CC ) )
5752, 56eqeltrrd 2274 . . . . . . . . 9  |-  ( ph  ->  ( r  e.  RR  |->  ( F `  r ) )  e.  ( RR
-cn-> CC ) )
5810recnd 8055 . . . . . . . . . 10  |-  ( ph  ->  U  e.  CC )
5953a1i 9 . . . . . . . . . 10  |-  ( ph  ->  CC  C_  CC )
60 cncfmptc 14832 . . . . . . . . . 10  |-  ( ( U  e.  CC  /\  RR  C_  CC  /\  CC  C_  CC )  ->  (
r  e.  RR  |->  U )  e.  ( RR
-cn-> CC ) )
6158, 51, 59, 60syl3anc 1249 . . . . . . . . 9  |-  ( ph  ->  ( r  e.  RR  |->  U )  e.  ( RR -cn-> CC ) )
6257, 61subcncf 14849 . . . . . . . 8  |-  ( ph  ->  ( r  e.  RR  |->  ( ( F `  r )  -  U
) )  e.  ( RR -cn-> CC ) )
63 cncfcdm 14818 . . . . . . . 8  |-  ( ( RR  C_  CC  /\  (
r  e.  RR  |->  ( ( F `  r
)  -  U ) )  e.  ( RR
-cn-> CC ) )  -> 
( ( r  e.  RR  |->  ( ( F `
 r )  -  U ) )  e.  ( RR -cn-> RR )  <-> 
( r  e.  RR  |->  ( ( F `  r )  -  U
) ) : RR --> RR ) )
6451, 62, 63syl2anc 411 . . . . . . 7  |-  ( ph  ->  ( ( r  e.  RR  |->  ( ( F `
 r )  -  U ) )  e.  ( RR -cn-> RR )  <-> 
( r  e.  RR  |->  ( ( F `  r )  -  U
) ) : RR --> RR ) )
6549, 64mpbird 167 . . . . . 6  |-  ( ph  ->  ( r  e.  RR  |->  ( ( F `  r )  -  U
) )  e.  ( RR -cn-> RR ) )
66 ivthreinc.i . . . . . . 7  |-  ( ph  ->  A. f ( f  e.  ( RR -cn-> RR )  ->  A. a  e.  RR  A. b  e.  RR  ( ( a  <  b  /\  (
f `  a )  <  0  /\  0  < 
( f `  b
) )  ->  E. x  e.  RR  ( a  < 
x  /\  x  <  b  /\  ( f `  x )  =  0 ) ) ) )
67 reex 8013 . . . . . . . . 9  |-  RR  e.  _V
6867mptex 5788 . . . . . . . 8  |-  ( r  e.  RR  |->  ( ( F `  r )  -  U ) )  e.  _V
69 eleq1 2259 . . . . . . . . 9  |-  ( f  =  ( r  e.  RR  |->  ( ( F `
 r )  -  U ) )  -> 
( f  e.  ( RR -cn-> RR )  <->  ( r  e.  RR  |->  ( ( F `
 r )  -  U ) )  e.  ( RR -cn-> RR ) ) )
70 fveq1 5557 . . . . . . . . . . . . . 14  |-  ( f  =  ( r  e.  RR  |->  ( ( F `
 r )  -  U ) )  -> 
( f `  a
)  =  ( ( r  e.  RR  |->  ( ( F `  r
)  -  U ) ) `  a ) )
7170breq1d 4043 . . . . . . . . . . . . 13  |-  ( f  =  ( r  e.  RR  |->  ( ( F `
 r )  -  U ) )  -> 
( ( f `  a )  <  0  <->  ( ( r  e.  RR  |->  ( ( F `  r )  -  U
) ) `  a
)  <  0 ) )
72 fveq1 5557 . . . . . . . . . . . . . 14  |-  ( f  =  ( r  e.  RR  |->  ( ( F `
 r )  -  U ) )  -> 
( f `  b
)  =  ( ( r  e.  RR  |->  ( ( F `  r
)  -  U ) ) `  b ) )
7372breq2d 4045 . . . . . . . . . . . . 13  |-  ( f  =  ( r  e.  RR  |->  ( ( F `
 r )  -  U ) )  -> 
( 0  <  (
f `  b )  <->  0  <  ( ( r  e.  RR  |->  ( ( F `  r )  -  U ) ) `
 b ) ) )
7471, 733anbi23d 1326 . . . . . . . . . . . 12  |-  ( f  =  ( r  e.  RR  |->  ( ( F `
 r )  -  U ) )  -> 
( ( a  < 
b  /\  ( f `  a )  <  0  /\  0  <  ( f `
 b ) )  <-> 
( a  <  b  /\  ( ( r  e.  RR  |->  ( ( F `
 r )  -  U ) ) `  a )  <  0  /\  0  <  ( ( r  e.  RR  |->  ( ( F `  r
)  -  U ) ) `  b ) ) ) )
75 fveq1 5557 . . . . . . . . . . . . . . 15  |-  ( f  =  ( r  e.  RR  |->  ( ( F `
 r )  -  U ) )  -> 
( f `  x
)  =  ( ( r  e.  RR  |->  ( ( F `  r
)  -  U ) ) `  x ) )
7675eqeq1d 2205 . . . . . . . . . . . . . 14  |-  ( f  =  ( r  e.  RR  |->  ( ( F `
 r )  -  U ) )  -> 
( ( f `  x )  =  0  <-> 
( ( r  e.  RR  |->  ( ( F `
 r )  -  U ) ) `  x )  =  0 ) )
77763anbi3d 1329 . . . . . . . . . . . . 13  |-  ( f  =  ( r  e.  RR  |->  ( ( F `
 r )  -  U ) )  -> 
( ( a  < 
x  /\  x  <  b  /\  ( f `  x )  =  0 )  <->  ( a  < 
x  /\  x  <  b  /\  ( ( r  e.  RR  |->  ( ( F `  r )  -  U ) ) `
 x )  =  0 ) ) )
7877rexbidv 2498 . . . . . . . . . . . 12  |-  ( f  =  ( r  e.  RR  |->  ( ( F `
 r )  -  U ) )  -> 
( E. x  e.  RR  ( a  < 
x  /\  x  <  b  /\  ( f `  x )  =  0 )  <->  E. x  e.  RR  ( a  <  x  /\  x  <  b  /\  ( ( r  e.  RR  |->  ( ( F `
 r )  -  U ) ) `  x )  =  0 ) ) )
7974, 78imbi12d 234 . . . . . . . . . . 11  |-  ( f  =  ( r  e.  RR  |->  ( ( F `
 r )  -  U ) )  -> 
( ( ( a  <  b  /\  (
f `  a )  <  0  /\  0  < 
( f `  b
) )  ->  E. x  e.  RR  ( a  < 
x  /\  x  <  b  /\  ( f `  x )  =  0 ) )  <->  ( (
a  <  b  /\  ( ( r  e.  RR  |->  ( ( F `
 r )  -  U ) ) `  a )  <  0  /\  0  <  ( ( r  e.  RR  |->  ( ( F `  r
)  -  U ) ) `  b ) )  ->  E. x  e.  RR  ( a  < 
x  /\  x  <  b  /\  ( ( r  e.  RR  |->  ( ( F `  r )  -  U ) ) `
 x )  =  0 ) ) ) )
8079ralbidv 2497 . . . . . . . . . 10  |-  ( f  =  ( r  e.  RR  |->  ( ( F `
 r )  -  U ) )  -> 
( A. b  e.  RR  ( ( a  <  b  /\  (
f `  a )  <  0  /\  0  < 
( f `  b
) )  ->  E. x  e.  RR  ( a  < 
x  /\  x  <  b  /\  ( f `  x )  =  0 ) )  <->  A. b  e.  RR  ( ( a  <  b  /\  (
( r  e.  RR  |->  ( ( F `  r )  -  U
) ) `  a
)  <  0  /\  0  <  ( ( r  e.  RR  |->  ( ( F `  r )  -  U ) ) `
 b ) )  ->  E. x  e.  RR  ( a  <  x  /\  x  <  b  /\  ( ( r  e.  RR  |->  ( ( F `
 r )  -  U ) ) `  x )  =  0 ) ) ) )
8180ralbidv 2497 . . . . . . . . 9  |-  ( f  =  ( r  e.  RR  |->  ( ( F `
 r )  -  U ) )  -> 
( A. a  e.  RR  A. b  e.  RR  ( ( a  <  b  /\  (
f `  a )  <  0  /\  0  < 
( f `  b
) )  ->  E. x  e.  RR  ( a  < 
x  /\  x  <  b  /\  ( f `  x )  =  0 ) )  <->  A. a  e.  RR  A. b  e.  RR  ( ( a  <  b  /\  (
( r  e.  RR  |->  ( ( F `  r )  -  U
) ) `  a
)  <  0  /\  0  <  ( ( r  e.  RR  |->  ( ( F `  r )  -  U ) ) `
 b ) )  ->  E. x  e.  RR  ( a  <  x  /\  x  <  b  /\  ( ( r  e.  RR  |->  ( ( F `
 r )  -  U ) ) `  x )  =  0 ) ) ) )
8269, 81imbi12d 234 . . . . . . . 8  |-  ( f  =  ( r  e.  RR  |->  ( ( F `
 r )  -  U ) )  -> 
( ( f  e.  ( RR -cn-> RR )  ->  A. a  e.  RR  A. b  e.  RR  (
( a  <  b  /\  ( f `  a
)  <  0  /\  0  <  ( f `  b ) )  ->  E. x  e.  RR  ( a  <  x  /\  x  <  b  /\  ( f `  x
)  =  0 ) ) )  <->  ( (
r  e.  RR  |->  ( ( F `  r
)  -  U ) )  e.  ( RR
-cn-> RR )  ->  A. a  e.  RR  A. b  e.  RR  ( ( a  <  b  /\  (
( r  e.  RR  |->  ( ( F `  r )  -  U
) ) `  a
)  <  0  /\  0  <  ( ( r  e.  RR  |->  ( ( F `  r )  -  U ) ) `
 b ) )  ->  E. x  e.  RR  ( a  <  x  /\  x  <  b  /\  ( ( r  e.  RR  |->  ( ( F `
 r )  -  U ) ) `  x )  =  0 ) ) ) ) )
8368, 82spcv 2858 . . . . . . 7  |-  ( A. f ( f  e.  ( RR -cn-> RR )  ->  A. a  e.  RR  A. b  e.  RR  (
( a  <  b  /\  ( f `  a
)  <  0  /\  0  <  ( f `  b ) )  ->  E. x  e.  RR  ( a  <  x  /\  x  <  b  /\  ( f `  x
)  =  0 ) ) )  ->  (
( r  e.  RR  |->  ( ( F `  r )  -  U
) )  e.  ( RR -cn-> RR )  ->  A. a  e.  RR  A. b  e.  RR  ( ( a  <  b  /\  (
( r  e.  RR  |->  ( ( F `  r )  -  U
) ) `  a
)  <  0  /\  0  <  ( ( r  e.  RR  |->  ( ( F `  r )  -  U ) ) `
 b ) )  ->  E. x  e.  RR  ( a  <  x  /\  x  <  b  /\  ( ( r  e.  RR  |->  ( ( F `
 r )  -  U ) ) `  x )  =  0 ) ) ) )
8466, 83syl 14 . . . . . 6  |-  ( ph  ->  ( ( r  e.  RR  |->  ( ( F `
 r )  -  U ) )  e.  ( RR -cn-> RR )  ->  A. a  e.  RR  A. b  e.  RR  (
( a  <  b  /\  ( ( r  e.  RR  |->  ( ( F `
 r )  -  U ) ) `  a )  <  0  /\  0  <  ( ( r  e.  RR  |->  ( ( F `  r
)  -  U ) ) `  b ) )  ->  E. x  e.  RR  ( a  < 
x  /\  x  <  b  /\  ( ( r  e.  RR  |->  ( ( F `  r )  -  U ) ) `
 x )  =  0 ) ) ) )
8565, 84mpd 13 . . . . 5  |-  ( ph  ->  A. a  e.  RR  A. b  e.  RR  (
( a  <  b  /\  ( ( r  e.  RR  |->  ( ( F `
 r )  -  U ) ) `  a )  <  0  /\  0  <  ( ( r  e.  RR  |->  ( ( F `  r
)  -  U ) ) `  b ) )  ->  E. x  e.  RR  ( a  < 
x  /\  x  <  b  /\  ( ( r  e.  RR  |->  ( ( F `  r )  -  U ) ) `
 x )  =  0 ) ) )
8645, 85, 5rspcdva 2873 . . . 4  |-  ( ph  ->  A. b  e.  RR  ( ( A  < 
b  /\  ( (
r  e.  RR  |->  ( ( F `  r
)  -  U ) ) `  A )  <  0  /\  0  <  ( ( r  e.  RR  |->  ( ( F `
 r )  -  U ) ) `  b ) )  ->  E. x  e.  RR  ( A  <  x  /\  x  <  b  /\  (
( r  e.  RR  |->  ( ( F `  r )  -  U
) ) `  x
)  =  0 ) ) )
8736, 86, 19rspcdva 2873 . . 3  |-  ( ph  ->  ( ( A  < 
B  /\  ( (
r  e.  RR  |->  ( ( F `  r
)  -  U ) ) `  A )  <  0  /\  0  <  ( ( r  e.  RR  |->  ( ( F `
 r )  -  U ) ) `  B ) )  ->  E. x  e.  RR  ( A  <  x  /\  x  <  B  /\  (
( r  e.  RR  |->  ( ( F `  r )  -  U
) ) `  x
)  =  0 ) ) )
8828, 87mpd 13 . 2  |-  ( ph  ->  E. x  e.  RR  ( A  <  x  /\  x  <  B  /\  (
( r  e.  RR  |->  ( ( F `  r )  -  U
) ) `  x
)  =  0 ) )
895adantr 276 . . . . . 6  |-  ( (
ph  /\  ( x  e.  RR  /\  ( A  <  x  /\  x  <  B  /\  ( ( r  e.  RR  |->  ( ( F `  r
)  -  U ) ) `  x )  =  0 ) ) )  ->  A  e.  RR )
9089rexrd 8076 . . . . 5  |-  ( (
ph  /\  ( x  e.  RR  /\  ( A  <  x  /\  x  <  B  /\  ( ( r  e.  RR  |->  ( ( F `  r
)  -  U ) ) `  x )  =  0 ) ) )  ->  A  e.  RR* )
9119adantr 276 . . . . . 6  |-  ( (
ph  /\  ( x  e.  RR  /\  ( A  <  x  /\  x  <  B  /\  ( ( r  e.  RR  |->  ( ( F `  r
)  -  U ) ) `  x )  =  0 ) ) )  ->  B  e.  RR )
9291rexrd 8076 . . . . 5  |-  ( (
ph  /\  ( x  e.  RR  /\  ( A  <  x  /\  x  <  B  /\  ( ( r  e.  RR  |->  ( ( F `  r
)  -  U ) ) `  x )  =  0 ) ) )  ->  B  e.  RR* )
93 simprl 529 . . . . 5  |-  ( (
ph  /\  ( x  e.  RR  /\  ( A  <  x  /\  x  <  B  /\  ( ( r  e.  RR  |->  ( ( F `  r
)  -  U ) ) `  x )  =  0 ) ) )  ->  x  e.  RR )
9490, 92, 933jca 1179 . . . 4  |-  ( (
ph  /\  ( x  e.  RR  /\  ( A  <  x  /\  x  <  B  /\  ( ( r  e.  RR  |->  ( ( F `  r
)  -  U ) ) `  x )  =  0 ) ) )  ->  ( A  e.  RR*  /\  B  e. 
RR*  /\  x  e.  RR ) )
95 simprr1 1047 . . . . 5  |-  ( (
ph  /\  ( x  e.  RR  /\  ( A  <  x  /\  x  <  B  /\  ( ( r  e.  RR  |->  ( ( F `  r
)  -  U ) ) `  x )  =  0 ) ) )  ->  A  <  x )
96 simprr2 1048 . . . . 5  |-  ( (
ph  /\  ( x  e.  RR  /\  ( A  <  x  /\  x  <  B  /\  ( ( r  e.  RR  |->  ( ( F `  r
)  -  U ) ) `  x )  =  0 ) ) )  ->  x  <  B )
9795, 96jca 306 . . . 4  |-  ( (
ph  /\  ( x  e.  RR  /\  ( A  <  x  /\  x  <  B  /\  ( ( r  e.  RR  |->  ( ( F `  r
)  -  U ) ) `  x )  =  0 ) ) )  ->  ( A  <  x  /\  x  < 
B ) )
98 elioo4g 10009 . . . 4  |-  ( x  e.  ( A (,) B )  <->  ( ( A  e.  RR*  /\  B  e.  RR*  /\  x  e.  RR )  /\  ( A  <  x  /\  x  <  B ) ) )
9994, 97, 98sylanbrc 417 . . 3  |-  ( (
ph  /\  ( x  e.  RR  /\  ( A  <  x  /\  x  <  B  /\  ( ( r  e.  RR  |->  ( ( F `  r
)  -  U ) ) `  x )  =  0 ) ) )  ->  x  e.  ( A (,) B ) )
1008adantr 276 . . . . . 6  |-  ( (
ph  /\  ( x  e.  RR  /\  ( A  <  x  /\  x  <  B  /\  ( ( r  e.  RR  |->  ( ( F `  r
)  -  U ) ) `  x )  =  0 ) ) )  ->  F : RR
--> RR )
101100, 93ffvelcdmd 5698 . . . . 5  |-  ( (
ph  /\  ( x  e.  RR  /\  ( A  <  x  /\  x  <  B  /\  ( ( r  e.  RR  |->  ( ( F `  r
)  -  U ) ) `  x )  =  0 ) ) )  ->  ( F `  x )  e.  RR )
102101recnd 8055 . . . 4  |-  ( (
ph  /\  ( x  e.  RR  /\  ( A  <  x  /\  x  <  B  /\  ( ( r  e.  RR  |->  ( ( F `  r
)  -  U ) ) `  x )  =  0 ) ) )  ->  ( F `  x )  e.  CC )
10358adantr 276 . . . 4  |-  ( (
ph  /\  ( x  e.  RR  /\  ( A  <  x  /\  x  <  B  /\  ( ( r  e.  RR  |->  ( ( F `  r
)  -  U ) ) `  x )  =  0 ) ) )  ->  U  e.  CC )
104 fveq2 5558 . . . . . . 7  |-  ( r  =  x  ->  ( F `  r )  =  ( F `  x ) )
105104oveq1d 5937 . . . . . 6  |-  ( r  =  x  ->  (
( F `  r
)  -  U )  =  ( ( F `
 x )  -  U ) )
10610adantr 276 . . . . . . 7  |-  ( (
ph  /\  ( x  e.  RR  /\  ( A  <  x  /\  x  <  B  /\  ( ( r  e.  RR  |->  ( ( F `  r
)  -  U ) ) `  x )  =  0 ) ) )  ->  U  e.  RR )
107101, 106resubcld 8407 . . . . . 6  |-  ( (
ph  /\  ( x  e.  RR  /\  ( A  <  x  /\  x  <  B  /\  ( ( r  e.  RR  |->  ( ( F `  r
)  -  U ) ) `  x )  =  0 ) ) )  ->  ( ( F `  x )  -  U )  e.  RR )
1082, 105, 93, 107fvmptd3 5655 . . . . 5  |-  ( (
ph  /\  ( x  e.  RR  /\  ( A  <  x  /\  x  <  B  /\  ( ( r  e.  RR  |->  ( ( F `  r
)  -  U ) ) `  x )  =  0 ) ) )  ->  ( (
r  e.  RR  |->  ( ( F `  r
)  -  U ) ) `  x )  =  ( ( F `
 x )  -  U ) )
109 simprr3 1049 . . . . 5  |-  ( (
ph  /\  ( x  e.  RR  /\  ( A  <  x  /\  x  <  B  /\  ( ( r  e.  RR  |->  ( ( F `  r
)  -  U ) ) `  x )  =  0 ) ) )  ->  ( (
r  e.  RR  |->  ( ( F `  r
)  -  U ) ) `  x )  =  0 )
110108, 109eqtr3d 2231 . . . 4  |-  ( (
ph  /\  ( x  e.  RR  /\  ( A  <  x  /\  x  <  B  /\  ( ( r  e.  RR  |->  ( ( F `  r
)  -  U ) ) `  x )  =  0 ) ) )  ->  ( ( F `  x )  -  U )  =  0 )
111102, 103, 110subeq0d 8345 . . 3  |-  ( (
ph  /\  ( x  e.  RR  /\  ( A  <  x  /\  x  <  B  /\  ( ( r  e.  RR  |->  ( ( F `  r
)  -  U ) ) `  x )  =  0 ) ) )  ->  ( F `  x )  =  U )
112 fveqeq2 5567 . . . 4  |-  ( c  =  x  ->  (
( F `  c
)  =  U  <->  ( F `  x )  =  U ) )
113112rspcev 2868 . . 3  |-  ( ( x  e.  ( A (,) B )  /\  ( F `  x )  =  U )  ->  E. c  e.  ( A (,) B ) ( F `  c )  =  U )
11499, 111, 113syl2anc 411 . 2  |-  ( (
ph  /\  ( x  e.  RR  /\  ( A  <  x  /\  x  <  B  /\  ( ( r  e.  RR  |->  ( ( F `  r
)  -  U ) ) `  x )  =  0 ) ) )  ->  E. c  e.  ( A (,) B
) ( F `  c )  =  U )
11588, 114rexlimddv 2619 1  |-  ( ph  ->  E. c  e.  ( A (,) B ) ( F `  c
)  =  U )
Colors of variables: wff set class
Syntax hints:    -> wi 4    /\ wa 104    <-> wb 105    /\ w3a 980   A.wal 1362    = wceq 1364    e. wcel 2167   A.wral 2475   E.wrex 2476    C_ wss 3157   class class class wbr 4033    |-> cmpt 4094   -->wf 5254   ` cfv 5258  (class class class)co 5922   CCcc 7877   RRcr 7878   0cc0 7879   RR*cxr 8060    < clt 8061    - cmin 8197   (,)cioo 9963   -cn->ccncf 14806
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-in1 615  ax-in2 616  ax-io 710  ax-5 1461  ax-7 1462  ax-gen 1463  ax-ie1 1507  ax-ie2 1508  ax-8 1518  ax-10 1519  ax-11 1520  ax-i12 1521  ax-bndl 1523  ax-4 1524  ax-17 1540  ax-i9 1544  ax-ial 1548  ax-i5r 1549  ax-13 2169  ax-14 2170  ax-ext 2178  ax-coll 4148  ax-sep 4151  ax-nul 4159  ax-pow 4207  ax-pr 4242  ax-un 4468  ax-setind 4573  ax-iinf 4624  ax-cnex 7970  ax-resscn 7971  ax-1cn 7972  ax-1re 7973  ax-icn 7974  ax-addcl 7975  ax-addrcl 7976  ax-mulcl 7977  ax-mulrcl 7978  ax-addcom 7979  ax-mulcom 7980  ax-addass 7981  ax-mulass 7982  ax-distr 7983  ax-i2m1 7984  ax-0lt1 7985  ax-1rid 7986  ax-0id 7987  ax-rnegex 7988  ax-precex 7989  ax-cnre 7990  ax-pre-ltirr 7991  ax-pre-ltwlin 7992  ax-pre-lttrn 7993  ax-pre-apti 7994  ax-pre-ltadd 7995  ax-pre-mulgt0 7996  ax-pre-mulext 7997  ax-arch 7998  ax-caucvg 7999
This theorem depends on definitions:  df-bi 117  df-stab 832  df-dc 836  df-3or 981  df-3an 982  df-tru 1367  df-fal 1370  df-nf 1475  df-sb 1777  df-eu 2048  df-mo 2049  df-clab 2183  df-cleq 2189  df-clel 2192  df-nfc 2328  df-ne 2368  df-nel 2463  df-ral 2480  df-rex 2481  df-reu 2482  df-rmo 2483  df-rab 2484  df-v 2765  df-sbc 2990  df-csb 3085  df-dif 3159  df-un 3161  df-in 3163  df-ss 3170  df-nul 3451  df-if 3562  df-pw 3607  df-sn 3628  df-pr 3629  df-op 3631  df-uni 3840  df-int 3875  df-iun 3918  df-br 4034  df-opab 4095  df-mpt 4096  df-tr 4132  df-id 4328  df-po 4331  df-iso 4332  df-iord 4401  df-on 4403  df-ilim 4404  df-suc 4406  df-iom 4627  df-xp 4669  df-rel 4670  df-cnv 4671  df-co 4672  df-dm 4673  df-rn 4674  df-res 4675  df-ima 4676  df-iota 5219  df-fun 5260  df-fn 5261  df-f 5262  df-f1 5263  df-fo 5264  df-f1o 5265  df-fv 5266  df-isom 5267  df-riota 5877  df-ov 5925  df-oprab 5926  df-mpo 5927  df-1st 6198  df-2nd 6199  df-recs 6363  df-frec 6449  df-map 6709  df-sup 7050  df-inf 7051  df-pnf 8063  df-mnf 8064  df-xr 8065  df-ltxr 8066  df-le 8067  df-sub 8199  df-neg 8200  df-reap 8602  df-ap 8609  df-div 8700  df-inn 8991  df-2 9049  df-3 9050  df-4 9051  df-n0 9250  df-z 9327  df-uz 9602  df-q 9694  df-rp 9729  df-xneg 9847  df-xadd 9848  df-ioo 9967  df-seqfrec 10540  df-exp 10631  df-cj 11007  df-re 11008  df-im 11009  df-rsqrt 11163  df-abs 11164  df-rest 12912  df-topgen 12931  df-psmet 14099  df-xmet 14100  df-met 14101  df-bl 14102  df-mopn 14103  df-top 14234  df-topon 14247  df-bases 14279  df-cn 14424  df-cnp 14425  df-tx 14489  df-cncf 14807
This theorem is referenced by:  ivthdichlem  14887
  Copyright terms: Public domain W3C validator