From f61cc6b34c4380025f9af03e009640800cc7ee22 Mon Sep 17 00:00:00 2001
From: ralfulrich <ralf.ulrich@kit.edu>
Date: Mon, 17 Jun 2019 06:29:28 +0200
Subject: [PATCH] update README about eigen3

---
 README.md | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index d5cf8f7c2..7762975eb 100644
--- a/README.md
+++ b/README.md
@@ -58,10 +58,13 @@ which are very useful also for us.
 
 CORSIKA 8 is tested regularly at least on gcc7.3.0 and clang-6.0.0.
 Additional software prerequisites: eigen3, boost, cmake, g++, git. 
+However, eigen3 is shipped in ThirdParty directory, so any installation 
+on the system is optional. 
 On a bare Ubuntu 18.04, just add:
 ```
-sudo apt install libeigen3-dev cmake g++ git
+sudo apt install cmake g++ git
 ```
+add ```libeigen3-dev``` if you want to use system version of eigen3.
 
 Follow these steps to download and install CORSIKA 8 milestone2
 ```
-- 
GitLab