I am trying to write a condition for a decision table and can’t seem to figure out how to do it.    

I have a global variable called area.  This is in sq. ft.

I have a fact called Item which has an attribute called weight.  This is in grams / sq. ft.

The Item comes from the attribute called value from a fact named Choice where the sku attribute matches what is in the rule

I want to compare the (weight * area) to the parameter for the row.  The parameter is being passed in as lbs.

Here is what I tried for my three condition columns:

CONDITION                                                            CONDITION                                                                                                                    CONDITION

mm : Choice                                                          

sku                                                                             exists(Item(weight * area > ($param * 453.5924)) from mm.value)                                                                                    exists(Item(weight * area <= ($param * 453.5924)) from mm.value)

This did not work.  This will work if I remove the formula and just do something like exists(Item(weight > $param) from mm.value).   So the syntax is correct except for the comparison that I want to do.

Any ideas on how to do this?

Thanks.