better readme

README.md

@@ -12,8 +12,20 @@ Windows installer can be found here: https://code.google.com/p/relational/downlo
 For Linux, check your distribution's packages, relational is available on Debian and Ubuntu.
 
 
-Usage
-=====
+Syntax
+======
+
+These are some valid queries
+
+```
+σage > 25 and rank == weight(A)
+σ (name.upper().startswith('J') and age>21 )(people)
+Q ᐅᐊ π a,b(A) ᐅᐊ B
+ρid➡i,name➡n(A) - π a,b(π a,b(A)) ᑎ σage > 25 or rank = weight(A)
+π a,b(π a,b(A))
+ρid➡i,name➡n(π a,b(A))
+A ᐅᐊ B
+```
 
 Formal language definition at this link https://github.com/ltworf/relational/wiki/Grammar-and-language
 
@@ -25,7 +37,9 @@ Run from sources
 
 To launch the application, run
 
-```./relational_gui.py```
+```
+./relational_gui.py
+```
 
 If it needs some dependencies:
 Qt4, Python 2.7, either PyQT4 or Pyside.