diff -r 1b5bf1029a9c -r 793aedbbe1c3 relpipe-data/classic-example.xml
--- a/relpipe-data/classic-example.xml	Sat Dec 01 21:24:29 2018 +0100
+++ b/relpipe-data/classic-example.xml	Sat Dec 01 22:11:23 2018 +0100
@@ -10,7 +10,7 @@
 			Assume that we have a text file containing a list of animals and their properties:
 		</p>
 		
-		<m:pre src="animals.txt"/>
+		<m:pre jazyk="text" src="animals.txt"/>
 				
 		<p>
 			We can pass this file through a pipeline: