I took the reference implementation extract extrfile_1.xml and added this to a test scenario. In the default reference implementation, it will generate the AM-GBL form as it has an ALWAYS trigger on it. I created a new trigger called NEVER, which does a RETURN(0);, and added it to the AM-GBL form. I ran the test, and the form triggered. In a truth table, (T AND F) = F, whereas (T OR F) = T. In this case, we have T OR F = T, therefore, when multiple triggers are specified on a resource, the system creates an OR condition.
If you want to create an AND condition, you can create a new trigger that combines all the possible logic combinations to generate your result. This is usually the accepted best practice.
Andy is correct and it gets even more complicated if you mix in a trigger that returns a count versus simple True/False. I too recommend that you combine your conditions into a single trigger - or make a new trigger that calls the two current triggers that you intend to mix together in an AND or OR situation.
We noticed a different behavior. We return Always (REturn 1) and Never as Return 0.
The overall result we got was that section printed according to the last trigger that's executed. So, if I have trigger executed in order 1,0 section is not printed. When the triggers execute in order 0,1 prints the section.
We are on 12.6 now. I remember in 11.4 or 12.1 to behave those as OR condition, does anyone know if its a bug in 12.6 or the intentional design change.