Two statements are equivalent if they have the same logical meaning, so that they cannot possibly differ in truth value. By the same token, each of two equivalent statements logically implies the other, and each can be substituted for the other in arguments without any change in validity.
Fs are all equivalent to one another.
Hs do not exist. But it is more practical to memorize a few simple rules or laws of equivalence rather than testing them repeatedly. The main laws of equivalence for simple categorical statements are summarized in the remainder of this document. Some Fs are non-Gs General Summary. All of these equivalences are summed up in the following charts, one for universal statements and one for existentials.