length(getvariables(dissect(F)))
ans =
   506

dissect(F)
+++++++++++++++++++++++++++++++++++++++++++++++++++++
|   ID|      Constraint|                        Type|
+++++++++++++++++++++++++++++++++++++++++++++++++++++
|   #1|   Numeric value|   Matrix inequality 252x252|
|   #2|   Numeric value|   Matrix inequality 251x251|
+++++++++++++++++++++++++++++++++++++++++++++++++++++
length(getvariables(dissect(F)))
ans =
   506