Talk:Q3075175

Область значений

@Infovarius:, ну тут либо это квадрат комплексного числе, тогда область значений - все комплексные числа, либо квадрат вещественного числа, тогда это неотрицательные вещественные числа. Просто вещественные числа - это непонятно для чего (объединение вещественных и чисто мнимых?). Wikisaurus (talk) 21:41, 22 April 2020 (UTC)

@Wikisaurus: это же "домен" (область прибытия), а не область значений, так что мы вправе поставить любое надмножество от неотрицательных :) --Infovarius (talk) 11:35, 24 April 2020 (UTC)

@慈居: Actually I meant image of function (P2396) which should be non-negative for real input. But now I completely confused by your adding "continuum" to so many places (properties, qualifiers...). May be Pids are suboptimal... What do you mean by them? --Infovarius (talk) 11:28, 12 September 2023 (UTC)

The domains and its images (and codomains) are not paired properly without qualifiers. We should be able to know "when" the image is $\mathbb {R} _{\geq 0}$ and when it is $\mathbb {C}$. By the way, sometimes "domain" as separators is not enough, e.g., if we want the square to have as the codomain Riemann surface of the square root (Q121600137), then the domain still has to be $\mathbb {C}$. 慈居 (talk) 21:58, 12 September 2023 (UTC)

Perhaps this will be clear if the qualifier is called "applies to domain" or something like that? But I have to confess that what I'd prefer is just to make "images" and "codomains" qualifiers of "domains", so that we don't have to repeat domains again and again. 慈居 (talk) 22:07, 12 September 2023 (UTC)

Yeah, I've understood about problem of pairing, I agree with current model. But problem of continuum still persists - $\mathbb {C}$ is a continuum too :) --Infovarius (talk) 19:14, 14 September 2023 (UTC)