Reading the documentation

[MRAB]

On 2017-08-25 02:58, Ben Bacarisse wrote:
> Chris Angelico <rosuav at gmail.com> writes:
> 
>> On Fri, Aug 25, 2017 at 11:25 AM, Ben Bacarisse <ben.usenet at bsb.me.uk> wrote:
>>> The use as a noun is not covered here, though it is only a small step
>>> from other places where membership of a mathematical set has turned the
>>> adjective into a noun.  "Rational" and "real" started out as adjectives,
>>> but their use as nouns is now widespread.  "The function returns a
>>> real".  "The result is a rational".  It's much less common for complex
>>> and integral, to the point that it sounds wrong to me.
>>
>> This is a common thing in English (and many other languages). When you
>> find yourself frequently using similar phrases, you abbreviate them:
>>
>> * real number -> real
>> * rational number -> rational
>> * complex number -> complex
>>
>> Thus the adjective acquires a new meaning as a noun. As my mother (and
>> grammar teacher) drummed into me: No word is a part of speech unless
>> it appears in context.
> 
> Yes, we agree on that, but has it become natural(!) yet with complex and
> integral?  Not to my ear.  What about yours?
> 
> To me, the "adjectiveness" is still so strong that my brain asks "an
> integral what?", "a complex what?".  That does not happen in my head
> with "a real" or "a rational".
> 
To me, an "integral" is the result of integration.

I'm OK with "real" as a noun, but only because I'm used to its use in 
programming.

"Complex" already has a meaning as a noun, though not mathematical.

But what about "imaginary"?