Metamath Proof Explorer


Theorem lcmineqlem9

Description: (1-x)^(N-M) is continuous. (Contributed by metakunt, 12-May-2024)

Ref Expression
Hypotheses lcmineqlem9.1
|- ( ph -> M e. NN )
lcmineqlem9.2
|- ( ph -> N e. NN )
lcmineqlem9.3
|- ( ph -> M <_ N )
Assertion lcmineqlem9
|- ( ph -> ( x e. CC |-> ( ( 1 - x ) ^ ( N - M ) ) ) e. ( CC -cn-> CC ) )

Proof

Step Hyp Ref Expression
1 lcmineqlem9.1
 |-  ( ph -> M e. NN )
2 lcmineqlem9.2
 |-  ( ph -> N e. NN )
3 lcmineqlem9.3
 |-  ( ph -> M <_ N )
4 nfv
 |-  F/ x ph
5 ax-1cn
 |-  1 e. CC
6 eqid
 |-  ( x e. CC |-> ( 1 - x ) ) = ( x e. CC |-> ( 1 - x ) )
7 6 sub2cncf
 |-  ( 1 e. CC -> ( x e. CC |-> ( 1 - x ) ) e. ( CC -cn-> CC ) )
8 5 7 mp1i
 |-  ( ph -> ( x e. CC |-> ( 1 - x ) ) e. ( CC -cn-> CC ) )
9 1 nnzd
 |-  ( ph -> M e. ZZ )
10 2 nnzd
 |-  ( ph -> N e. ZZ )
11 znn0sub
 |-  ( ( M e. ZZ /\ N e. ZZ ) -> ( M <_ N <-> ( N - M ) e. NN0 ) )
12 9 10 11 syl2anc
 |-  ( ph -> ( M <_ N <-> ( N - M ) e. NN0 ) )
13 3 12 mpbid
 |-  ( ph -> ( N - M ) e. NN0 )
14 expcncf
 |-  ( ( N - M ) e. NN0 -> ( y e. CC |-> ( y ^ ( N - M ) ) ) e. ( CC -cn-> CC ) )
15 13 14 syl
 |-  ( ph -> ( y e. CC |-> ( y ^ ( N - M ) ) ) e. ( CC -cn-> CC ) )
16 ssidd
 |-  ( ph -> CC C_ CC )
17 oveq1
 |-  ( y = ( 1 - x ) -> ( y ^ ( N - M ) ) = ( ( 1 - x ) ^ ( N - M ) ) )
18 4 8 15 16 17 cncfcompt2
 |-  ( ph -> ( x e. CC |-> ( ( 1 - x ) ^ ( N - M ) ) ) e. ( CC -cn-> CC ) )