Find the shortest route from node $1$ to node $7$ in the network shown.

could you provide it in LINGO while using this line:

@for$($note$($j$)$: @sum$($edge$($i$,$j$)$: inflow$($i$,$j$))=$@sum$($edge$($j$,$k$)$: outflow$($j$,$k$))$

$)$;