Metamath Proof Explorer


Theorem iistmd

Description: The closed unit interval forms a topological monoid under multiplication. (Contributed by Thierry Arnoux, 25-Mar-2017)

Ref Expression
Hypothesis df-iis
|- I = ( ( mulGrp ` CCfld ) |`s ( 0 [,] 1 ) )
Assertion iistmd
|- I e. TopMnd

Proof

Step Hyp Ref Expression
1 df-iis
 |-  I = ( ( mulGrp ` CCfld ) |`s ( 0 [,] 1 ) )
2 cnnrg
 |-  CCfld e. NrmRing
3 nrgtrg
 |-  ( CCfld e. NrmRing -> CCfld e. TopRing )
4 eqid
 |-  ( mulGrp ` CCfld ) = ( mulGrp ` CCfld )
5 4 trgtmd
 |-  ( CCfld e. TopRing -> ( mulGrp ` CCfld ) e. TopMnd )
6 2 3 5 mp2b
 |-  ( mulGrp ` CCfld ) e. TopMnd
7 unitsscn
 |-  ( 0 [,] 1 ) C_ CC
8 1elunit
 |-  1 e. ( 0 [,] 1 )
9 iimulcl
 |-  ( ( x e. ( 0 [,] 1 ) /\ y e. ( 0 [,] 1 ) ) -> ( x x. y ) e. ( 0 [,] 1 ) )
10 9 rgen2
 |-  A. x e. ( 0 [,] 1 ) A. y e. ( 0 [,] 1 ) ( x x. y ) e. ( 0 [,] 1 )
11 nrgring
 |-  ( CCfld e. NrmRing -> CCfld e. Ring )
12 4 ringmgp
 |-  ( CCfld e. Ring -> ( mulGrp ` CCfld ) e. Mnd )
13 2 11 12 mp2b
 |-  ( mulGrp ` CCfld ) e. Mnd
14 cnfldbas
 |-  CC = ( Base ` CCfld )
15 4 14 mgpbas
 |-  CC = ( Base ` ( mulGrp ` CCfld ) )
16 cnfld1
 |-  1 = ( 1r ` CCfld )
17 4 16 ringidval
 |-  1 = ( 0g ` ( mulGrp ` CCfld ) )
18 cnfldmul
 |-  x. = ( .r ` CCfld )
19 4 18 mgpplusg
 |-  x. = ( +g ` ( mulGrp ` CCfld ) )
20 15 17 19 issubm
 |-  ( ( mulGrp ` CCfld ) e. Mnd -> ( ( 0 [,] 1 ) e. ( SubMnd ` ( mulGrp ` CCfld ) ) <-> ( ( 0 [,] 1 ) C_ CC /\ 1 e. ( 0 [,] 1 ) /\ A. x e. ( 0 [,] 1 ) A. y e. ( 0 [,] 1 ) ( x x. y ) e. ( 0 [,] 1 ) ) ) )
21 13 20 ax-mp
 |-  ( ( 0 [,] 1 ) e. ( SubMnd ` ( mulGrp ` CCfld ) ) <-> ( ( 0 [,] 1 ) C_ CC /\ 1 e. ( 0 [,] 1 ) /\ A. x e. ( 0 [,] 1 ) A. y e. ( 0 [,] 1 ) ( x x. y ) e. ( 0 [,] 1 ) ) )
22 7 8 10 21 mpbir3an
 |-  ( 0 [,] 1 ) e. ( SubMnd ` ( mulGrp ` CCfld ) )
23 1 submtmd
 |-  ( ( ( mulGrp ` CCfld ) e. TopMnd /\ ( 0 [,] 1 ) e. ( SubMnd ` ( mulGrp ` CCfld ) ) ) -> I e. TopMnd )
24 6 22 23 mp2an
 |-  I e. TopMnd