[protege-discussion] empty frame value

[Thomas Russ]

On Jun 19, 2008, at 10:45 AM, Len Yabloko wrote:

> For example, if some algorithm implemented with Protege API needs to  
> decide when some slot value can be overwritten. The rule could be:  
> if value was never set, then it can be set only once, next time it  
> can not be set until it is reset to 'empty'. Normally setting value  
> to null would do that, but Protege does not allow it (I get  
> Assertion when set slot value to null).

Try  Frame.removeOwnSlotValue instead.