Document(
 Prefix(ex <http://example.org/example#>)
 Prefix(func <http://www.w3.org/2007/rif-builtin-function#>)
 Prefix(pred <http://www.w3.org/2007/rif-builtin-predicate#>)

 Group ( 
  Forall ?X ?C (
   If 
      And( ?X[ex:count -> ?C] pred:numeric-greater-than(?C 0) )
   Then Do ( 
      Modify (?X[ex:count-> func:numeric-subtract(?C 1)])
   )
  )

  ex:foo[ex:count -> 10]

 )
)