@david_chisnall I'm all with you, but it made me think about the nature of natural language ambiguity. It seems it's all/mostly a matter of them *allowing* us to say things without well-defined conditions for their truth etc. Natural language *could* certainly be used to say pretty much anything unambiguously, but that would be a very regimented *use* of natural language resources. And learning to use your language that way would be quite as hard as learning any formal language.