anchor.diff:      let vArray = Array.zeroCreate (Seq.length vertices) in
       let mutable vMap = Map.empty in
       let mutable eMap = Map.empty in
  +
  +    //cretae vertex map
       for i in 0 .. (Seq.length vertices - 1) do
           Array.set vArray i (ctx.MkBoolConst ("v" + (string i)));
           vMap <- Map.add (Seq.item i vertices)  i vMap;
       let eArray = Array.zeroCreate (Seq.length edges) in
  +
  +    // create edge map
       for i in 0 .. (Seq.length edges - 1) do
  -        // find vertices at the start and end of an edge for implication between edges and vertices for connectivity
           Array.set eArray i (ctx.MkBoolConst ("e" + (string i)));
           eMap <- Map.add (Seq.item i edges) i eMap;
  +
       let mutable condSet = Set.empty in
       let src = Map.find input.Start vMap in
       condSet <- Set.add (Array.get vArray src) condSet ;
  
positive.code:         let exp = ctx.MkAtMost(arr, 1) in
          condSet <- Set.add exp condSet;
  
          let arr = Array.create 2 vArray.[a] in
          Array.set arr 1 vArray.[b];
          let ends = ctx.MkAnd arr in
          let exp = ctx.MkImplies (eArray.[i], ends) in
          condSet <- Set.add exp condSet;
      let finalExp = ctx.MkAnd (Set.toArray condSet) in
  
      // relationship between nodes with the same topological location
      // identify using CgState.Node field which gives the topo.node
      // basically put all of these variables in one set and use a mutual
      //implication statement?
      //use Start and End in CGraph, map them to topological node and use
      // them for first connectivity constraint
      ctx.MkSolver ()
  
  let runTest =
  
negative.code:     // if a vertex is true, atleast one incoming edge is true, and atleast one outgoign edge
      for i in 0 .. (Seq.length vertices - 1) do
          // find vertices at the start and end of an edge for implication between edges and vertices for connectivity
          let vertex = Seq.item i vertices in   
  
          // atleast one incoming edge is true
          let incoming = input.Graph.InEdges vertex in
  