message: change minor typos
diff: @@ -3023,7 +3023,7 @@ def trace(x, name=None):
  in x. If x is of rank `k` with shape `[I, J, K, ..., L, M, N]`, then output
  is a tensor of rank `k-2` with dimensions `[I, J, K, ..., L]` where
  - `output[i, j, k, ..., l] = trace(x[i, j, i, ..., l, :, :])`
  + `output[i, j, k, ..., l] = trace(x[i, j, k, ..., l, :, :])`
  For example:
  