def pool_capacity_rule(m, l):
    expr = 0
    for j in [jj for (ll, jj) in con_pool_prod if (ll == l)]:
        expr += m.y[(l, j)]
    return (None, expr, pool_size[l])
def pool_capacity_rule(m, l):
    expr = 0
    for j in [jj for (ll, jj) in con_pool_prod if (ll == l)]:
        expr += m.y[(l, j)]
    return (None, expr, pool_size[l])