As a shorthand, it is possible to move an assignment from the
<Behaviour> code insert to the WOM element whose attribute
it updates. The element
<Text output value::input~value>means the same as
<Text output>
...
<Behaviour rexx>
{ $output~setValue( $input~getValue ) }
</Behaviour>
Dynamic attribute assignments do not require the $ marking an
instance, or the get part of the method name.