Added comments, fixed arguments mistake

src/porepy/numerics/fv/biot.py

@@ -899,7 +899,7 @@ def assemble_int_bound_displacement_trace(
         displacement on internal boundaries.
 
         The intended use is when the internal boundary is coupled to another
-        node. Specific usage depends on the
+        node in the GridBucket sence. Specific usage depends on the
         interface condition between the nodes; this method will typically be
         used to impose displacement continuity on an interface.
 
@@ -951,7 +951,7 @@ def assemble_int_bound_displacement_trace(
         else:
             cc[2, self_ind] += proj_avg * bp
 
-    def enforce_neumann_int_bound(self, _, _, _, _, _):
+    def enforce_neumann_int_bound(self, *_):
         pass
 
 
@@ -1148,7 +1148,7 @@ def assemble_int_bound_stress(
         cc[self_ind, 2] += biot_alpha * bound_div_d * proj_int.T
         rhs[self_ind] += biot_alpha * bound_div_d * proj_int.T * lam_k
 
-    def enforce_neumann_int_bound(self, _, _, _, _, _):
+    def enforce_neumann_int_bound(self, *_):
         pass
 
 

src/porepy/numerics/fv/mpsa.py

@@ -384,24 +384,24 @@ def assemble_int_bound_displacement_trace(
                 * matrix_dictionary["bound_displacement_face"]
                 * proj_int.T
             )
+            # Add the contibution to the displacement for the other side (master/slave).
+            # This can typically happen if you simulate the contact between the two
+            # sides of a fracture. The interaction region around the nodes on the end of
+            # the fracture will then get a contribution from both sides. We need a
+            # negative sign because the tractions T_s = -T_m has different sign.
             cc[2, 2] -= (
                 proj_avg
                 * weight
                 * hf2f
                 * matrix_dictionary["bound_displacement_face"]
                 * proj_int_swap.T
             )
-
         else:
+            # For comments look above
             cc[2, self_ind] += proj_avg * bp
             cc[2, 2] += (
                 proj_avg * matrix_dictionary["bound_displacement_face"] * proj_int.T
             )
-            # Add the contibution to the displacement for the other mortar. This can
-            # typically happen if you simulate the contact between the two sides of a
-            # fracture. The interaction region around the nodes on the edge will then
-            # get a contribution from both sides. We need a negative sign because the
-            # tractions T_s = -T_m has different sign.
             cc[2, 2] -= (
                 proj_avg
                 * matrix_dictionary["bound_displacement_face"]