def feed_availability_rule(m, i):
    expr = 0
    for l in [ll for (ii, ll) in con_feed_pool if (ii == i)]:
        for j in [jj for (ll, jj) in con_pool_prod if (ll == l)]:
            expr += (m.q[(i, l)] * m.y[(l, j)])
    for j in [jj for (ii, jj) in con_feed_prod if (ii == i)]:
        expr += m.z[(i, l)]
    return (min_flow[i], expr, max_flow[i])
def feed_availability_rule(m, i):
    expr = 0
    for l in [ll for (ii, ll) in con_feed_pool if (ii == i)]:
        for j in [jj for (ll, jj) in con_pool_prod if (ll == l)]:
            expr += (m.q[(i, l)] * m.y[(l, j)])
    for j in [jj for (ii, jj) in con_feed_prod if (ii == i)]:
        expr += m.z[(i, l)]
    return (min_flow[i], expr, max_flow[i])