diff --git a/boundary_graph_penrose_v2.txt b/boundary_graph_penrose_v2.txt
index e0dc4e2..fcfb3bf 100644
--- a/boundary_graph_penrose_v2.txt
+++ b/boundary_graph_penrose_v2.txt
@@ -1809,7 +1809,7 @@ The starting point is the classical totally-trapped-region theorem
 
    5. This B_b is the first (BLACK) inner boundary surface.
 
-   6. Now consider the complement Y = Omega_0 \ int(B_b), which has
+   6. Now consider the complement Y = Omega_0 minus int(B_b), which has
       an inner boundary (from B_b) with expansion c_b < 0 for K
       and an outer boundary (the sphere S_{R_0}) with positive
       expansion for K. Consider the tensor -K instead.
@@ -1828,7 +1828,7 @@ The starting point is the classical totally-trapped-region theorem
       (they are separated by the two-component structure of the
       construction).
 
-   9. Let Omega be the connected component of Omega_0 \ (int B_b
+   9. Let Omega be the connected component of Omega_0 minus (int B_b
       union int B_w) that reaches infinity. Its boundary B is
       (B_b retained) union (B_w retained), i.e., the subset of those
       surfaces adjacent to Omega.