diff --git a/engine-proto/gram-test/Engine.jl b/engine-proto/gram-test/Engine.jl
index ac5fe54..22f5914 100644
--- a/engine-proto/gram-test/Engine.jl
+++ b/engine-proto/gram-test/Engine.jl
@@ -59,11 +59,10 @@ nullmix = [Matrix{Int64}(I, 3, 3) zeros(Int64, 3, 2); zeros(Int64, 2, 3) [-1 1;
 unmix = [Matrix{Int64}(I, 3, 3) zeros(Int64, 3, 2); zeros(Int64, 2, 3) [-1 1; 1 1]]
 
 # the Lorentz form
-## [old] Q = diagm([1, 1, 1, 1, -1])
 Q = [Matrix{Int64}(I, 3, 3) zeros(Int64, 3, 2); zeros(Int64, 2, 3) [0 -2; -2 0]]
 
-# project a matrix onto the subspace of matrices whose entries vanish at the
-# given indices
+# project a matrix onto the subspace of matrices whose entries vanish away from
+# the given indices
 function proj_to_entries(mat, indices)
   result = zeros(size(mat))
   for (j, k) in indices