If the values of two different taxonomies on a post are the same, then…

I have two custom taxonomies: ‘writer’ and ‘artist’. If the writer and artist are different individuals, I wish to display the post’s content one way, but if the writer and artist are the same, I wish to display the post’s content another way.

I have no idea how to compare two different taxonomies to see if their values on a particular post match. (Here’s to hoping it’s something really obvious rather than something impossible!)