anchor.diff:      let inline (|DeleteNodeCall|_|) (callExpr: Expr) =
           match callExpr with
           | SpecificCall <@ deleteNode @> (_, _, [node]) -> Some node
  +        | _ -> None
  +
  +    let inline (|DeleteRelationshipCall|_|) (callExpr: Expr) =
  +        match callExpr with
  +        | SpecificCall <@ deleteRelationship @> (_, _, [rel]) -> Some rel
           | _ -> None
   
       let inline (|MatchNodeCall|_|) (callExpr: Expr) =
  
positive.code:         | Sequential(MatchNodeCall(nodeArg), rest) ->
              let matchExpr = nodeCypherExpr nodeArg
              printfn "MatchNode: %A (expr: %s)" nodeArg matchExpr
              executeRest (cypher.Match(matchExpr)) rest
  
          | Sequential(AnyMatchRelation(node1, rel, node2) as matchRel, rest) ->
              let relCypherExpr (r: Expr) =
  
negative.code: 
              printfn "MatchRelation: %s" matchExpr
              let newCypher = cypher.Match(matchExpr)
              executeWhere newCypher rest
  
          | _ -> unhandledExpr q
  
  