Archived tweet #11967 from the @leastfixedpoint Twitter Archive

@disconcision Here's a criterion that accepts 1-3 and rejects the rest (4&6 are almost, but not quite, ok; 5 is irredeemable): a kind of transitivity. Judge (x OP1 y OP2 z) "ok" if (x OP1 y) and (y OP2 z) implies both x OP1 z and x OP2 z.