def urbanmain() = {
import M5b._
//println(optimise(load_bff("benchmark.bf")).length)
//println(optimise(load_bff("mandelbrot.bf")).length)
val urban_l1 = optimise(load_bff("benchmark.bf")).length
val urban_l2 = optimise(load_bff("mandelbrot.bf")).length
assert(urban_l1 == 181)
assert(urban_l2 == 11203)
}