Originally posted by: stathis_d

Hello  guys,

I am wondering if there is a way to write a nested conditional expression on opl. I am trying to formulate the following: 

  forall (t in Period:t<g) , forall (v in Vehicles), forall (j in Destinations), forall  (<v,g , capacity> in available  :(v in Vehicles), (g in  Period))

 if  x[j][v][t] =1 then c[v][g]=0 except if capacity>0 then c[v][g]=capacity 

x[j][v][t]  is a binary variable, c[v][g] is variable capacity  and capacity is given.  I am trying to avoid to use  the capacity of a truck in the next period if it has already been used one period before except if  it seems available in the data for a future period.  

Regards

Hi

have you tried logical constraints like

(x[j][v][t]==1) == (c[v][g]==capacity);

?

regards

Originally posted by: stathis_d

Hi Alex, 

thanks for your answer. I'm just wondering what the equality means between the parenthesis, i knew only that  the sign of greater than on equal (=>) between two parenthesis is the expression  if ... then 

Hi

This == means is equivalent to

regards