The words predicate, proposition, relation, and so on are affected by many variations in usage. Some of their uses are associated with philosophical habits unlikely to change any time soon. But there are a number of compromise positions and technical strategies that allow us to negotiate between the variant practices and render them understandable in terms of each other.
I found that start of a reply in my phone’s draft folder. It’s been a month’s hard labor putting our house on the market and it looks like the busy-ness is just getting under way — so I’ll post that much to remind me what I need to do when I get my concentration and computer back on line.