In the last week I asked here on ELL two questions:
The answer for the first question is "inflectionally gradable for comparison and analytically gradable for comparison".
The answer for the second question as I understood by reading all the answers there, is that the word "up" is not an adjective and therefore it should not be gradable. But when I see Cambridge dictionary we can see that there is an adjective which is called "up". In addition in the same dictionary the word "upper" is marked as adjective. (and the word "lower" is marked there as a opposite. unlike the most of the answers in the second post). So it confuses me because I'm not sure if the word "up" is gradable or no.
Then my question is: Are there adjectives that are non gradable at all?