@prefix : <http://cwmTest/>.

        @prefix log: <http://www.w3.org/2000/10/swap/log#>.
	  @prefix math: <http://www.w3.org/2000/10/swap/math#> .

{ ?a :hasValue ?x. ?b :hasValue ?y.  ?b :hasValue ?z. 

  (?x  [ is math:sum of (?y ?z)  ]) math:sum ?d } => {?d :worksWith ?y}.

:a1 :hasValue 2.

:a2 :hasValue 0.
:a2 :hasValue 0.