inline use of antlib with namespace?

Given that I have installed an external ant task library in an appropriate location, I know of two ways to make the tasks accessible in a build script:

1. Add an xmlns attribute to some element, such as

   <project ... xmlns:resolver="antlib:org.apache.maven.resolver.ant" ... > 

2. Add a taskdef inline, such as

  <taskdef resource="org/apache/maven/resolver/ant/antlib.xml"/> 

The first method puts the tasks in a separate namespace. The second method adds the tasks to the current namespace.

What I would like is a method that can be used inline (like #2) and also puts the tasks in a separate namespace (like #1).

Is there a way to do this?

My motivation is to use the inline definition in an imported script, so that I don’t have to repeat the definition in a large number of project specific scripts.