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13:12:47
loginoob
I'm reading CL-gentle introduction to symbolic computation. How can i check if my answers are correct for the exercises
13:18:53
loginoob
I am not able to answer the question: PRove by contradiction that circular list cannot be constructed using just CONS. My answer from what i understood is that cons take two argument and i cannot give reference of first cell as second argument.
13:22:49
_death
loginoob: to do this indirect proof, you first assume that you can create a circular list using just CONS
13:23:24
_death
loginoob: then, you follow the consequence of this premise together with the definition he presents and arrive at a contradiction
13:26:44
beach
loginoob: To create a cell, the successor cell must already exist. I think you can derive a contradiction from that.
13:26:49
_death
since you arrived at a contradiction solely by using this premise and the definition (and the rules and axioms of logic), the premise must be false
13:28:18
_death
but beach is right.. I doubt gentle is meant to require knowledge of natural deduction :)
13:28:43
loginoob
so, let's say circular list contains three elements A B C and by making it from cons i have to cons A with cdr of C but that would make an infinite list and making it more than three elements so i cannot construct it using cons. Is that right by contradiction?
13:56:43
_death
a circular list looks like #1=(X . #1#) ... assume it was created by just using cons. then, #1# must have been passed to cons in the cdr position, but #1# has not yet been created at that time..
14:02:53
loginoob
_death: A cell is created after C and to point C to A cell A must have been created before C so that's the contradiction. ok, got it. Thank you :)
15:43:05
comborico1611
How do you automatically log into channels which require registered nicknames, when the nickserv executes after autologin executes?
15:54:22
comborico1611
Hmm. That's got to be one of the stranger things of the computing world. Reminds me of something like inventing the aersol can before the wheel.
18:33:14
fiddlerwoaroof
Xach: unless someone else has volunteered, I'd like to take over maintainership of linedit
18:35:51
fiddlerwoaroof
I'm not sure what the right way to go about this is, since the current maintainer is unresponsive
19:00:25
rme
I want to make a ccl 1.12 release pretty soon. We currently bundle ASDF 3.2.0. Will upgrading to ASDF 3.3.1 cause more harm than good?
20:12:14
khrbt
fiddlerwoaroof: Xach had suggested moving linedit to sharplispers. 2018-01-18.log:[04:57:11] <Xach> khrbt: maybe we could move the github one to sharplispers and call it canon? i can check with nikodemus
20:24:12
fiddlerwoaroof
Although, linedit is only broken because madeira-port doesn't work with ASDF-3.3.1, which makes the fix a little tricky
20:25:17
fiddlerwoaroof
Because, unless previous versions of ASDF support :if-feature, we have to either do something fancy or choose between forwards and backwards compatibility
20:40:00
pjb
I still have loader files, only they setup asdf:*central-registry*, and use quickload to load the system. ;-)
20:41:02
pjb
rme: it is better if the asdf version is consistent with what is provided by the other implementations.
20:47:28
pjb
users would have to locate an asdf and load it themselves. That said, this still has to be implemented for when a newer version is needed.
20:54:32
khrbt
doesn't quicklisp also include its own copy of asdf? If most people use quicklisp, wouldn't they get automatically get asdf too?
21:30:07
attila_lendvai
khrbt: asdf goes out of his way to detect old versions and upgrade them if needed, while avoid accidentally downgrading. all maintained lisps ship with a relatively fresh asdf, while the one in ql is rather old, so it's practically irrelevant that it's there.
21:32:18
attila_lendvai
fiddlerwoaroof: and others don't like cruft accumulating due to a strict backward compatibility policy. not updating is always an option... especially since DVCS and tags made integration that much easier
21:37:19
fiddlerwoaroof
I generally dislike the accumulation of cruft due to backwards compatibility
21:37:36
fiddlerwoaroof
But, the more important something is to a language, the more important backwards compatibility is
21:44:38
fiddlerwoaroof
If I had my preference, the build system for a language would never make a backwards incompatible change
22:28:12
jeosol_
I need some help guys. I have been getting this error in my backtrace: 0: (SB-VM::TAIL-CALL-SYMBOL 19 19 0) and that the function "some-package-name::get-cell-p0" is not defined. The latter function is a macro that takes 3 arguments
22:28:21
jeosol_
The get-cell-p0 is a function, but it is generated automatically by a macro when I start the application.
22:31:15
Bike
never seen that before, but it's not an error. the actual error is that your thing isn't defined?
22:38:32
jeosol_
@bike: (LOOP FOR POINT ACROSS #(0 1 2 3) COLLECT (FUNCALL (INTERN (FORMAT NIL "GET-CELL-P~A" POINT)) I J K))
22:39:13
jeosol_
That is the call I am making. I am constructing the actual function to call on the fly, and this is usually not known ahead of time. So I generated several functions by macro when I start