diff --git a/.gitignore b/.gitignore
index 8a9403a28..ca5549561 100644
--- a/.gitignore
+++ b/.gitignore
@@ -23,6 +23,7 @@ jni/libs/
 .buildinfo
 bazel-*
 *.pyc
+.idea*
 
-cmake-build
+cmake-build*
 small-blas-benchmarks
\ No newline at end of file
diff --git a/internal/ceres/linear_least_squares_problems.cc b/internal/ceres/linear_least_squares_problems.cc
index ab75e6e9c..0ce37e81a 100644
--- a/internal/ceres/linear_least_squares_problems.cc
+++ b/internal/ceres/linear_least_squares_problems.cc
@@ -160,13 +160,15 @@ std::unique_ptr<LinearLeastSquaresProblem> LinearLeastSquaresProblem0() {
              12    0    1   17   1
               0   30    1    1  37]
 
+      cond(A'A) = 200.36
+
       S = [ 42.3419  -1.4000  -11.5806
             -1.4000   2.6000    1.0000
            -11.5806   1.0000   31.1935]
 
       r = [ 4.3032
             5.4000
-            5.0323]
+            4.0323]
 
       S\r = [ 0.2102
               2.1367
diff --git a/internal/ceres/partitioned_matrix_view.h b/internal/ceres/partitioned_matrix_view.h
index 36a345066..130572035 100644
--- a/internal/ceres/partitioned_matrix_view.h
+++ b/internal/ceres/partitioned_matrix_view.h
@@ -54,7 +54,7 @@ namespace ceres::internal {
 
 // Given generalized bi-partite matrix A = [E F], with the same block
 // structure as required by the Schur complement based solver, found
-// in explicit_schur_complement_solver.h, provide access to the
+// in schur_complement_solver.h, provide access to the
 // matrices E and F and their outer products E'E and F'F with
 // themselves.
 //
diff --git a/internal/ceres/partitioned_matrix_view_impl.h b/internal/ceres/partitioned_matrix_view_impl.h
index 967620b6b..a33b86d86 100644
--- a/internal/ceres/partitioned_matrix_view_impl.h
+++ b/internal/ceres/partitioned_matrix_view_impl.h
@@ -55,7 +55,7 @@ PartitionedMatrixView<kRowBlockSize, kEBlockSize, kFBlockSize>::
   // in E maybe less than the number of row blocks in the input matrix
   // as some of the row blocks at the bottom may not have any
   // e_blocks. For a definition of what an e_block is, please see
-  // explicit_schur_complement_solver.h
+  // schur_complement_solver.h
   num_row_blocks_e_ = 0;
   for (const auto& row : bs->rows) {
     const std::vector<Cell>& cells = row.cells;
@@ -228,7 +228,7 @@ void PartitionedMatrixView<kRowBlockSize, kEBlockSize, kFBlockSize>::
 // Given a range of columns blocks of a matrix m, compute the block
 // structure of the block diagonal of the matrix m(:,
 // start_col_block:end_col_block)'m(:, start_col_block:end_col_block)
-// and return a BlockSparseMatrix with the this block structure. The
+// and return a BlockSparseMatrix with this block structure. The
 // caller owns the result.
 template <int kRowBlockSize, int kEBlockSize, int kFBlockSize>
 std::unique_ptr<BlockSparseMatrix>