
Open: 
Open set 

Open: 
Open ball 

Open: 
Open ball in
Lp 

Open: 
Approximation of borel set, by closed, open subsets 

Open: 
Sigmacompactness preserved on open
sets 

Open: 
Strong sigmacompactness preserved on open
sets 

Open: 
L. finite measure on open
subset of Rn is regular 

Open: 
Cont. with compact supp between compact and open 

Open: 
Continuous with compact support, open
subset of Rn 

Orthogonal: 
Orthogonal of a set 

Orthogonal: 
Orthogonal projection 

Orthogonal: 
Orthogonal matrix 

Outermeasure: 
Outermeasure 

Outermeasure: 
Sigmaalgebra associated with outermeasure 

Outermeasure: 
Outermeasure theorem 

Outerregular: 
Innerregular, outerregular and
regular measure 

Outerregular: 
L. finite measure on scompact metric is outerregular 

Outerregular: 
L. f. measure on open subset of Rn is outerregular 