diff --git a/dataflow_neuro/cell_lib_async.act b/dataflow_neuro/cell_lib_async.act
index e6b8e6a..cb76535 100644
--- a/dataflow_neuro/cell_lib_async.act
+++ b/dataflow_neuro/cell_lib_async.act
@@ -276,6 +276,20 @@ namespace tmpl {
             y {-1}; _y{-1}}
         }
 
+        export defcell A_2C_RB_X4 (bool ! y; bool? c1, c2, pr_B, sr_B; bool? vdd, vss)
+        {
+        bool _y;
+        prs{
+            (~c1 & ~c2) | ~pr_B -> _y+
+            c1 & c2 & sr_B -> _y-
+            _y => y-
+        }
+        sizing {    
+                leak_adjust <- 1; 
+                p_n_mode <- 1;
+            y {-4}; _y{-1}}
+        }
+
         export defcell A_2C_R_X1 (bool ! y; bool? c1, c2, pr_B, sr_B; bool? vdd, vss)
         {
         prs{
@@ -478,24 +492,24 @@ namespace tmpl {
                 p_n_mode <- 1;
             y {-1}}
         }
-        export defcell arbiter_handshake(bool in1_r, in1_a,in2_r, in2_a out_r, out_a)
-        {
-          bool _u, _v;
-          A_2C_B_X1 cel1(.c1 = out_a,.c2 = v,.y = in1_a);
-          A_2C_B_X1 cel2(.c1 = out_a,.c2 = u,.y = in2_a);
-          prs {
-           [keeper=0]  in1_v &  _v -> _u-
-           [keeper=0] ~in1_v  | ~_v  -> _u+
-           [keeper=0]  in2_v &  _u -> _v-
-           [keeper=0] ~in2_v  | ~_u  -> _v+
-           [keeper=0] ~_u | ~in2_a  => u+
-           [keeper=0] ~_v | ~in1_a  => v+
-           [keeper=0] u | v  => out_r 
-          }
-          spec {
-            mk_excllo(_u, _v)
-          }
-        }
+        // export defcell arbiter_handshake(bool in1_r, in1_a,in2_r, in2_a out_r, out_a)
+        // {
+        //   bool _u, _v;
+        //   A_2C_B_X1 cel1(.c1 = out_a,.c2 = v,.y = in1_a);
+        //   A_2C_B_X1 cel2(.c1 = out_a,.c2 = u,.y = in2_a);
+        //   prs {
+        //    [keeper=0]  in1_v &  _v -> _u-
+        //    [keeper=0] ~in1_v  | ~_v  -> _u+
+        //    [keeper=0]  in2_v &  _u -> _v-
+        //    [keeper=0] ~in2_v  | ~_u  -> _v+
+        //    [keeper=0] ~_u | ~in2_a  => u+
+        //    [keeper=0] ~_v | ~in1_a  => v+
+        //    [keeper=0] u | v  => out_r 
+        //   }
+        //   spec {
+        //     mk_excllo(_u, _v)
+        //   }
+        // }
         }}