Metamath Proof Explorer


Theorem blsconn

Description: An open ball in the complex numbers is simply connected. (Contributed by Mario Carneiro, 12-Feb-2015)

Ref Expression
Hypotheses blsconn.j
|- J = ( TopOpen ` CCfld )
blsconn.s
|- S = ( P ( ball ` ( abs o. - ) ) R )
blsconn.k
|- K = ( J |`t S )
Assertion blsconn
|- ( ( P e. CC /\ R e. RR* ) -> K e. SConn )

Proof

Step Hyp Ref Expression
1 blsconn.j
 |-  J = ( TopOpen ` CCfld )
2 blsconn.s
 |-  S = ( P ( ball ` ( abs o. - ) ) R )
3 blsconn.k
 |-  K = ( J |`t S )
4 cnxmet
 |-  ( abs o. - ) e. ( *Met ` CC )
5 blssm
 |-  ( ( ( abs o. - ) e. ( *Met ` CC ) /\ P e. CC /\ R e. RR* ) -> ( P ( ball ` ( abs o. - ) ) R ) C_ CC )
6 4 5 mp3an1
 |-  ( ( P e. CC /\ R e. RR* ) -> ( P ( ball ` ( abs o. - ) ) R ) C_ CC )
7 2 6 eqsstrid
 |-  ( ( P e. CC /\ R e. RR* ) -> S C_ CC )
8 2 blcvx
 |-  ( ( ( P e. CC /\ R e. RR* ) /\ ( x e. S /\ y e. S /\ t e. ( 0 [,] 1 ) ) ) -> ( ( t x. x ) + ( ( 1 - t ) x. y ) ) e. S )
9 7 8 1 3 cvxsconn
 |-  ( ( P e. CC /\ R e. RR* ) -> K e. SConn )