diff --git a/README.md b/README.md
index 54db10e..b408d7a 100644
--- a/README.md
+++ b/README.md
@@ -2,7 +2,7 @@
 
 It's a simple minimal lisp interpreter written by ruby.
 
-Still INCOMPLETE.
+
 
 ### usage
 
diff --git a/prol.rb b/prol.rb
index 766e9fc..a1749c5 100644
--- a/prol.rb
+++ b/prol.rb
@@ -102,6 +102,7 @@ def lisp_eval(elem, env = $global_env)
 end
 
 $copyleft = "Copyleft (Ↄ) 2021 vonhyou@lenva.tech
+(PRO)cessor of (L)ist for Mathmatical Calculation
 This is an open source software, you can view it's source code on github:
 https://github.com/vonhyou/lisp-interpreter\n\n"
 
diff --git a/screenshot/demo.png b/screenshot/demo.png
new file mode 100644
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