Using the Ant build tool
In the Eclipse context menu you can do a 'right mouse click' on the
build.xml file and choose menu 'Run As... -> Ant build...'
JRE tab of the appearing dialog you should set a
Separate JRE to a Java Development Kit (JDK) version 1.7 or higher.
Target tab of the dialog you can select the Ant target you would like to run:
- jar - creates the uncompressed
- proguard-library - creates the compressed and obfuscated
/build/jar/symja-lib-YYYY-MM-DD.jarfile with the Proguard tool