Aggregate Sums within records on one form using a Formula field in a second form

Aggregate Sums within records on one form using a Formula field in a second form

Form Job has a Formula fields named  Total_Labor_Hrs , Labor_Rate , and Total_Labor_Charges.
Total_Labor_Hrs * Labor_Rate = Total_Labor_Charges.

Form Log records the hours worked on the various jobs via a Look_up field named Job which looks up to the form Job; and also has a field named Labor_Hrs.

Would it be possible to use a Formula field in a Job record to aggregate the Labor_Hrs from all Log records related to that Job? Would the expression below be allowed within a Formula field in the Form Job named   Total_Labor_Charges ?

  Log[ Job == input.ID].sum( Labor_Hrs) *  Labor_Rate