Add support for count iterating operator.
Example
'count (long i in 0...arr->len | arr->ptr[i] >= 0) == arr->len / 2'

This would probably entail changing 'exists' and 'forall' to the following (parentheses required)
'exists (long i in 0...arr->len | arr->ptr[i] >= 0)'
'forall (long i in 0...arr->len | arr->ptr[i] >= 0)'
That would remove all shift/reduce conflicts from the OCL parser.  Not sure if this is worth doing though.