Description: Closure theorem for Knopp's function. (Contributed by Asger C. Ipsen, 26-Jul-2021)
Ref | Expression | ||
---|---|---|---|
Hypotheses | knoppcld.t | |- T = ( x e. RR |-> ( abs ` ( ( |_ ` ( x + ( 1 / 2 ) ) ) - x ) ) ) |
|
knoppcld.f | |- F = ( y e. RR |-> ( n e. NN0 |-> ( ( C ^ n ) x. ( T ` ( ( ( 2 x. N ) ^ n ) x. y ) ) ) ) ) |
||
knoppcld.w | |- W = ( w e. RR |-> sum_ i e. NN0 ( ( F ` w ) ` i ) ) |
||
knoppcld.a | |- ( ph -> A e. RR ) |
||
knoppcld.n | |- ( ph -> N e. NN ) |
||
knoppcld.1 | |- ( ph -> C e. RR ) |
||
knoppcld.2 | |- ( ph -> ( abs ` C ) < 1 ) |
||
Assertion | knoppcld | |- ( ph -> ( W ` A ) e. CC ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | knoppcld.t | |- T = ( x e. RR |-> ( abs ` ( ( |_ ` ( x + ( 1 / 2 ) ) ) - x ) ) ) |
|
2 | knoppcld.f | |- F = ( y e. RR |-> ( n e. NN0 |-> ( ( C ^ n ) x. ( T ` ( ( ( 2 x. N ) ^ n ) x. y ) ) ) ) ) |
|
3 | knoppcld.w | |- W = ( w e. RR |-> sum_ i e. NN0 ( ( F ` w ) ` i ) ) |
|
4 | knoppcld.a | |- ( ph -> A e. RR ) |
|
5 | knoppcld.n | |- ( ph -> N e. NN ) |
|
6 | knoppcld.1 | |- ( ph -> C e. RR ) |
|
7 | knoppcld.2 | |- ( ph -> ( abs ` C ) < 1 ) |
|
8 | 1 2 3 5 6 7 | knoppcn | |- ( ph -> W e. ( RR -cn-> CC ) ) |
9 | cncff | |- ( W e. ( RR -cn-> CC ) -> W : RR --> CC ) |
|
10 | 8 9 | syl | |- ( ph -> W : RR --> CC ) |
11 | 10 4 | ffvelrnd | |- ( ph -> ( W ` A ) e. CC ) |