Calls a simple swap function with pointers inscrutable (the only hard to decipher character is the asterisk), and as a good counterexample provides this ?
Like other folks have said, show the equivalent C program and then we can have a discussion about implementation complexity and comprehensibility.
Do note that the equivalent C program permits IPC between two instances of the program that could be either running on the same machine or could be running on different machines connected by an IP network.
Edit: For general information, here's an Erlang implementation of increment and swap. Swap is made a bit complicated because Erlang doesn't support multiple returns... returning a tuple or list is the way that's handled, so I had it accept a two-element tuple for consistency with what it returns:
Decades long C programmer here. C is hard to parse. The thing is, you get used to it and then it feels like it is normal, but it really isn't. Not as bad as Perl, but pretty bad. And it is easy to construct one liners that are tricky to understand, I think C is the only language that has an obfuscation contest that keeps turning up gems year after year.
