Function varisat::context::set_var_count

pub fn set_var_count(
    ctx: Mut<WatchlistsP, Mut<VsidsP, Mut<TmpFlagsP, Mut<ImplGraphP, Mut<BinaryClausesP, Mut<AssignmentP, Mut<AnalyzeConflictP, Ref<Context>>>>>>>>, 
    count: usize
)

Update structures for a new variable count.