<ExtensionAttribute()>
Public Overloads Shared Function Or(Of T)( _
   ByVal left As Expression(Of Func(Of T,Boolean)), _
   ByVal right As Expression(Of Func(Of T,Boolean)) _
) As Expression(Of Func(Of T,Boolean))

Dim left As Expression(Of Func(Of T,Boolean))
Dim right As Expression(Of Func(Of T,Boolean))
Dim value As Expression(Of Func(Of T,Boolean))
 
value = PredicateBuilder.Or(Of T)(left, right)

[ExtensionAttribute()]
public static Expression<Func<T,bool>> Or<T>( 
   Expression<Func<T,bool>> left,
   Expression<Func<T,bool>> right
)

[ExtensionAttribute()]
public:
static Expression<Func<T^,bool>^>^ Orgeneric<typename T>
( 
   Expression<Func<T^,bool>^>^ left,
   Expression<Func<T^,bool>^>^ right
) 

public void OrQuery() {
  var mgr = new DomainModelEntityManager();
  Expression<Func<Customer, bool>> crit1 = c => c.Country.Equals("Mexico");
  Expression<Func<Customer, bool>> crit2 = c => c.CompanyName.StartsWith("A");

  // Where companyname starts with A or country = mexico
  var finalcrit = crit1.Or(crit2);
  var query = mgr.Customers.Where(finalcrit);
  var list = query.ToList();
}