If I remember correctly, you’re Russian? Those Slavic double negatives must be giving you constant distress, if you’re so bothered by (seeming) deficiencies of logic in natural language.
It technically is redundant, though, because it has the form (A=>~B)&(B=>~A), while A=>~B and B=>~A are equivalent to each other. It doesn’t need to be symmetrized because the statement was symmetric in the first place, even if it wasn’t stated in an obviously symmetric form such as ~(A&B). (Going to have to say I like the redundant version for emphasis, though.)
The logical redundancy in this phrase has long bothered me.
If I remember correctly, you’re Russian? Those Slavic double negatives must be giving you constant distress, if you’re so bothered by (seeming) deficiencies of logic in natural language.
It’s not redundant; it’s a more witty and elegant way of saying that there are some new things, some true things, but none that are both.
It technically is redundant, though, because it has the form (A=>~B)&(B=>~A), while A=>~B and B=>~A are equivalent to each other. It doesn’t need to be symmetrized because the statement was symmetric in the first place, even if it wasn’t stated in an obviously symmetric form such as ~(A&B). (Going to have to say I like the redundant version for emphasis, though.)