To save others the effort, I did some spelunking and found a Hello World in a tutorial. Here it is: :- module hello. :- interface. :- import_module io.

To save others the effort, I did some spelunking and found a Hello World in a tutorial. Here it is: :- module hello. :- interface. :- import_module io. :- pred main(io::di, io::uo) is det. :- implementation. main(IOState_in, IOState_out) :- io.write_string("Hello, World!\n", IOState_in, IOState_out).