Originally posted by: viva0521

Hi, there

I am duplicating one of my lingo model to opl. Here I have one constraint in lingo as:

@For(path(i,j,o,d) | j#EQ#1 #and# j#NE#o #and# j#NE#d #AND# i#NE#o #and# i#NE#d #and# i#GE#9  #and# i#LE#10:x(i,j,o,d)= 0);

(i,j) here are the node index and supposed to be integer.This is to restrict the flow on specific arc is equal to 0. 

So I tried following:

forall ( i, j in node, j == 1, j != o, j != d, i != o, i != d,  i == 9, i == 10) flow [i] [j] [o] [d] ==0.

It didn't work, any idea? Thanks in advance!

Hi

instead of

forall ( i, j in node, j == 1, j != o, j != d, i != o, i != d,  i == 9, i == 10)

can you try

forall ( i, j in node : (j == 1) && ( j != o) &&  (j != d)  &&  (i != o) &&  (i != d) &&  (i == 9) && (i == 10))

?

regards

Originally posted by: viva0521

Alex, thanks a lot! It works now. I really appreciate your valuable comments!

By the way, when I was trying to output my optimal solution, I wrote:

It is said for(i,j in Node, o in Ori, d in Dest) missing ")" after Node, I am wondering what is wrong here? Thanks again!

Hi,

because in the scripting part, the syntax for "for" is not the same as for "forall"

Instead of

for(i,j in Node, o in Ori, d in Dest)

try

for(i in Node) for (j in Node) for( o in Ori) for( d in Dest)

regards