I agree in general but I do wonder how unusual using ‘all’ to assume existence is. For example “have you done all your homework?” What we are really asking is whether there is any homework that wasn’t done, not did you do any homework.
Fair enough, and this seems to emphasize the notion that being explicit about the tacit rules of natural-language usage is not easy.
Fair enough, and this seems to emphasize the notion that being explicit about the tacit rules of natural-language usage is not easy.