I am looking for a program that deals with relational algebra on relations and relationships.

Here's a link to "relational", which is a GUIbased relational algebra application. According to the site, it is an "educational tool" so I'm not sure if it's exactly what you're looking for or not. You should be able to install it by running the following command from a terminal session:



Maybe Sage has some capabilities that would be useful to you? It's a multipurpose CAS. If not, here is a thick report on Relational Algebra that I couldn't make heads or tails ofnot even to figure out where the software that the author is talking about is available. 

