[BioC] merging two sets of genes

[kfbargad@ehu.es]

Dear Robert, thanks for your comments, they were very useful. I am 
just practicing how to work with lists, comparing and merging, finding 
genes in lists, etc. 

If I have two lists, say A and B, and want to create a third one 
containing the genes present in A but not in B, should I use the 
vennDiagram() function to obtain this? maybe something similar to

[-grep(geneNames(B)]

would be useful?

I had a look at your suggestion of using %in% but couldn´t find much 
information about how to use it

Any hints would be greatly appreciated,

Best

David