From 9020ba0247c14b3203d54c7bb4145d9ffe5ef5cb Mon Sep 17 00:00:00 2001
From: zhenzhenxiang <405090724@163.com>
Date: Wed, 11 Nov 2020 20:46:46 +0800
Subject: [PATCH] Update algo_walkthrough.rst (#1545)

Fix typos.

Signed-off-by: zhenzhenxiang <405090724@163.com>
---
 docs/source/algo_walkthrough.rst | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/docs/source/algo_walkthrough.rst b/docs/source/algo_walkthrough.rst
index 483dcf5..42b056a 100644
--- a/docs/source/algo_walkthrough.rst
+++ b/docs/source/algo_walkthrough.rst
@@ -276,9 +276,9 @@ The resulting net is called the "*pose graph*".
 
     Constraints can be visualized in RViz, it is very handy to tune global SLAM. One can also toggle ``POSE_GRAPH.constraint_builder.log_matches`` to get regular reports of the constraints builder formatted as histograms.
 
-- Non-global constraints (also known as inter submaps constraints) are built automatically between nodes that are closely following each other on a trajectory.
+- Non-global constraints (also known as intra submaps constraints) are built automatically between nodes that are closely following each other on a trajectory.
   Intuitively, those "*non-global ropes*" keep the local structure of the trajectory coherent.
-- Global constraints (also referred to as loop closure constraints or intra submaps contraints) are regularly searched between a new submap and previous nodes that are considered "*close enough*" in space (part of a certain **search window**) and a strong fit (a good match when running scan matching).
+- Global constraints (also referred to as loop closure constraints or inter submaps contraints) are regularly searched between a new submap and previous nodes that are considered "*close enough*" in space (part of a certain **search window**) and a strong fit (a good match when running scan matching).
   Intuitively, those "*global ropes*" introduce knots in the structure and firmly bring two strands closer.
 
 .. code-block:: lua