i think that problem 8 isnt actually 1 song you sort of have to think of each album as 1 song

now for problem 8 i think it is made up of undertow aenima and salival in a 34 song track list

because "Problem 8 (The Riemann Hypothesis)" is exactly 34 characters long (including spaces and brackets) and if you ad up the songs from those 3 albums it comes to 34

1 intolerance
2 prison sex
3 sober
4 bottom
5 crawl away
6 swamp song
7 undertow
8 4°
9 flood
10 disgustipated
11 track 69
12 stinkfist
13 eulogy
14 h.
15 useful idiot
16 forty six & 2
17 message to harry manback
18 hooker with a penis
19 intermission
20 jimmy
21 die eier von satan
22 pushit
23 cesaro summability
24 aenema
25 (-)ions
26 third eye
27 third eye (live)
28 part of me (live)
29 pushit (live)
30 message to harry manback II
31 merkaba (live)
32 you lied (live)
33 no quarter
34 L.A.M.C.

but the songs wouldnt be played in that order if you read my post on how tool spells out the album/band name then youll know what i mean

it can be found here : https://toolnavy.com/showthread.php?t=126706

so for the problem 8 you would spell out "Problem 8 (The Riemann Hypothesis)"
and you would probably put the songs that spell out the band name "TOOL" where the spaces are and the brackets would be one of the live songs or (-) ions

as for the 8 im not too sure it since theres no tool song in that list (or otherwise) that has the number 8 in it might be track 8 on one of the albums it could be opiATE it could be H. cause H is the 8th letter of the alphabet (though H. is probably the H in Hypothesis)

or when those songs are properly assembled it could actually spell out the word "EIGHT"