Grice on (Ex) and 'some'

It is a well-known fact about logic that you can say,

"Tom has dogs"

even if he only has one.

Apparently,

the expression

(Ex)Dx & H(t,x)

--- i.e. there is an x such that x is a dog and Tom has it -- does not ENTAIL that there is more than one x. Reciprocally, --

Grice has "Ex" to read: "some (at least one)".

Cfr.

"Some dog is owned by Tom"

with

"Some dogs ARE owned by Tom".

Same quantifier: 'some (at least one)'.

The clearest statement of this fact about the use of "some" and the plural is in Warnock, "Metaphysics in Logic," though -- broadly endorsing a Gricean approach.

This below from a more recent source:

Eytan Zweig (2009).

Number-Neutral Bare Plurals and the Multiplicity Implicature. Linguistics and Philosophy 32 (4).

Bare plurals ("dogs") behave in ways that quantified plurals ("some dogs") do not. For instance, while the sentence "John owns dogs" implies [implicates, but does not entail. JLS] "John owns more than one dog," its negation "John does not own dogs" does not mean “John does not own more than one dog”, but rather “John does not own a dog” ([at all. JLS]. A second puzzling behavior is known as the dependent plural reading; when in the scope of another plural, the ‘more than one’ (...)"