What name describes the theory of the strength of a logical statement? Most people on this site are familiar with the idea of the "strength" of a statement. Ignoring the validity of the statements themselves, "All primes are even." is a logically weaker statement than "All integers are even." Even the statement "All integers except 7 are even." still seems qualitatively stronger than "All primes are even." even though neither implies the other.
What name describes the theory of the relative strength of logical statements? I've tried searching for a variety of keywords but have turned up surprisingly little besides references to the "intuitive" definitions like that above.

I agree with the above comments; $B{\implies}A$ in conjunction with $A\not\equiv B$ is the only context I can think of offhand where it is unambiguous to say that statement $B$ is stronger than $A,$ so I think that's a fair characterisation of statement strength. If there is a specific descriptor for this, I have never heard of it.

Addendum
I think the more interesting cases are where one statement is not a clear superset of the other. I've updated my question to clarify this.
In this case (including in your specified example), any assertion about the two statements' relative strength would be ambiguous in sense; on the other hand, there is no controversy in claiming that one statement is satisfied by more entities than the other statement.
