0prjspn (#3243)

remove extra $d from rabeqdv and df-prjspn; altho more are found by the 
checkdv.py script

move rnmptc, eceq2i, and eceq2d to main

many utils: rabeqcda rabdif iunsn imaopab fnimasnd dfqs2 dfqs3 qsalrel

add section comment for projective spaces and expand explanation of 
df-prjsp

prjspval2 isn't actually used yet but it's shorter

Co-authored-by: Wolf Lammen <[email protected]>

Author: icecream17

changes-set.txt

@@ -27,7 +27,10 @@ make a github issue.)
 
 DONE:
 Date      Old       New         Notes
+ 8-Jun-23 rnmptc    [same]      moved from GS's mathbox to main set.mm
  8-Jun-23 eqneltri  [same]      moved from GS's mathbox to main set.mm
+ 6-Jun-23 eceq2i    [same]      moved from PM's mathbox to main set.mm
+ 6-Jun-23 eceq2d    [same]      moved from PM's mathbox to main set.mm
  6-Jun-23 2sqmo     [same]      moved from TA's mathbox to main set.mm
  6-Jun-23 2sqmod    [same]      moved from TA's mathbox to main set.mm
  6-Jun-23 2sqn0     [same]      moved from TA's mathbox to main set.mm