Metamath Proof Explorer


Theorem cvmsss

Description: An even covering is a subset of the topology of the domain (i.e. a collection of open sets). (Contributed by Mario Carneiro, 11-Feb-2015)

Ref Expression
Hypothesis cvmcov.1
|- S = ( k e. J |-> { s e. ( ~P C \ { (/) } ) | ( U. s = ( `' F " k ) /\ A. u e. s ( A. v e. ( s \ { u } ) ( u i^i v ) = (/) /\ ( F |` u ) e. ( ( C |`t u ) Homeo ( J |`t k ) ) ) ) } )
Assertion cvmsss
|- ( T e. ( S ` U ) -> T C_ C )

Proof

Step Hyp Ref Expression
1 cvmcov.1
 |-  S = ( k e. J |-> { s e. ( ~P C \ { (/) } ) | ( U. s = ( `' F " k ) /\ A. u e. s ( A. v e. ( s \ { u } ) ( u i^i v ) = (/) /\ ( F |` u ) e. ( ( C |`t u ) Homeo ( J |`t k ) ) ) ) } )
2 1 cvmsi
 |-  ( T e. ( S ` U ) -> ( U e. J /\ ( T C_ C /\ T =/= (/) ) /\ ( U. T = ( `' F " U ) /\ A. u e. T ( A. v e. ( T \ { u } ) ( u i^i v ) = (/) /\ ( F |` u ) e. ( ( C |`t u ) Homeo ( J |`t U ) ) ) ) ) )
3 2 simp2d
 |-  ( T e. ( S ` U ) -> ( T C_ C /\ T =/= (/) ) )
4 3 simpld
 |-  ( T e. ( S ` U ) -> T C_ C )