0.830 * [progress]: [Phase 1 of 3] Setting up.
0.001 * * * [progress]: [1/2] Preparing points
0.255 * * * [progress]: [2/2] Setting up program.
0.258 * [progress]: [Phase 2 of 3] Improving.
0.261 * [simplify]: Simplifying using  #<procedure:simplify-batch-regraph> :
   (/ (- (+ f n)) (- f n))
0.264 * * [simplify]: iteration  0 :  6  enodes  (cost  8 )
0.268 * * [simplify]: iteration  1 :  13  enodes  (cost  8 )
0.270 * * [simplify]: iteration  2 :  16  enodes  (cost  8 )
0.271 * * [simplify]: iteration  3 :  20  enodes  (cost  8 )
0.273 * * [simplify]: iteration  4 :  26  enodes  (cost  8 )
0.276 * * [simplify]: iteration  5 :  31  enodes  (cost  8 )
0.279 * * [simplify]: iteration  6 :  32  enodes  (cost  8 )
0.282 * * [simplify]: iteration  done :  32  enodes  (cost  8 )
0.282 * [simplify]: Simplified to:
   (/ (- (+ f n)) (- f n))
0.284 * * [progress]: iteration 1 / 4
0.284 * * * [progress]: picking best candidate
0.285 * * * * [pick]: Picked  #<alt (λ (f n) (/ (- (+ f n)) (- f n)))>
0.286 * * * [progress]: localizing error
0.294 * * * [progress]: generating rewritten candidates
0.294 * * * * [progress]: [ 1 / 1 ] rewriting at (2)
0.320 * * * [progress]: generating series expansions
0.320 * * * * [progress]: [ 1 / 1 ] generating series at (2)
0.325 * [approximate]: Taking taylor expansion of (* -1 (/ (+ n f) (- f n))) in (f n) around 0
0.326 * [taylor]: Taking taylor expansion of (* -1 (/ (+ n f) (- f n))) in n
0.326 * [taylor]: Taking taylor expansion of -1 in n
0.326 * [taylor]: Taking taylor expansion of (/ (+ n f) (- f n)) in n
0.326 * [taylor]: Taking taylor expansion of (+ n f) in n
0.326 * [taylor]: Taking taylor expansion of n in n
0.326 * [taylor]: Taking taylor expansion of f in n
0.326 * [taylor]: Taking taylor expansion of (- f n) in n
0.326 * [taylor]: Taking taylor expansion of f in n
0.326 * [taylor]: Taking taylor expansion of n in n
0.327 * [taylor]: Taking taylor expansion of (* -1 (/ (+ n f) (- f n))) in f
0.327 * [taylor]: Taking taylor expansion of -1 in f
0.327 * [taylor]: Taking taylor expansion of (/ (+ n f) (- f n)) in f
0.327 * [taylor]: Taking taylor expansion of (+ n f) in f
0.327 * [taylor]: Taking taylor expansion of n in f
0.327 * [taylor]: Taking taylor expansion of f in f
0.327 * [taylor]: Taking taylor expansion of (- f n) in f
0.327 * [taylor]: Taking taylor expansion of f in f
0.327 * [taylor]: Taking taylor expansion of n in f
0.327 * [taylor]: Taking taylor expansion of (* -1 (/ (+ n f) (- f n))) in f
0.327 * [taylor]: Taking taylor expansion of -1 in f
0.327 * [taylor]: Taking taylor expansion of (/ (+ n f) (- f n)) in f
0.327 * [taylor]: Taking taylor expansion of (+ n f) in f
0.327 * [taylor]: Taking taylor expansion of n in f
0.327 * [taylor]: Taking taylor expansion of f in f
0.327 * [taylor]: Taking taylor expansion of (- f n) in f
0.327 * [taylor]: Taking taylor expansion of f in f
0.327 * [taylor]: Taking taylor expansion of n in f
0.328 * [taylor]: Taking taylor expansion of 1 in n
0.330 * [taylor]: Taking taylor expansion of (* 2 (/ 1 n)) in n
0.330 * [taylor]: Taking taylor expansion of 2 in n
0.330 * [taylor]: Taking taylor expansion of (/ 1 n) in n
0.330 * [taylor]: Taking taylor expansion of n in n
0.342 * [taylor]: Taking taylor expansion of (* 2 (/ 1 (pow n 2))) in n
0.342 * [taylor]: Taking taylor expansion of 2 in n
0.342 * [taylor]: Taking taylor expansion of (/ 1 (pow n 2)) in n
0.342 * [taylor]: Taking taylor expansion of (pow n 2) in n
0.342 * [taylor]: Taking taylor expansion of n in n
0.347 * [taylor]: Taking taylor expansion of (* 2 (/ 1 (pow n 3))) in n
0.348 * [taylor]: Taking taylor expansion of 2 in n
0.348 * [taylor]: Taking taylor expansion of (/ 1 (pow n 3)) in n
0.348 * [taylor]: Taking taylor expansion of (pow n 3) in n
0.348 * [taylor]: Taking taylor expansion of n in n
0.353 * [approximate]: Taking taylor expansion of (* -1 (/ (+ (/ 1 f) (/ 1 n)) (- (/ 1 f) (/ 1 n)))) in (f n) around 0
0.353 * [taylor]: Taking taylor expansion of (* -1 (/ (+ (/ 1 f) (/ 1 n)) (- (/ 1 f) (/ 1 n)))) in n
0.353 * [taylor]: Taking taylor expansion of -1 in n
0.353 * [taylor]: Taking taylor expansion of (/ (+ (/ 1 f) (/ 1 n)) (- (/ 1 f) (/ 1 n))) in n
0.353 * [taylor]: Taking taylor expansion of (+ (/ 1 f) (/ 1 n)) in n
0.353 * [taylor]: Taking taylor expansion of (/ 1 f) in n
0.353 * [taylor]: Taking taylor expansion of f in n
0.353 * [taylor]: Taking taylor expansion of (/ 1 n) in n
0.353 * [taylor]: Taking taylor expansion of n in n
0.354 * [taylor]: Taking taylor expansion of (- (/ 1 f) (/ 1 n)) in n
0.354 * [taylor]: Taking taylor expansion of (/ 1 f) in n
0.354 * [taylor]: Taking taylor expansion of f in n
0.354 * [taylor]: Taking taylor expansion of (/ 1 n) in n
0.354 * [taylor]: Taking taylor expansion of n in n
0.355 * [taylor]: Taking taylor expansion of (* -1 (/ (+ (/ 1 f) (/ 1 n)) (- (/ 1 f) (/ 1 n)))) in f
0.355 * [taylor]: Taking taylor expansion of -1 in f
0.355 * [taylor]: Taking taylor expansion of (/ (+ (/ 1 f) (/ 1 n)) (- (/ 1 f) (/ 1 n))) in f
0.355 * [taylor]: Taking taylor expansion of (+ (/ 1 f) (/ 1 n)) in f
0.355 * [taylor]: Taking taylor expansion of (/ 1 f) in f
0.355 * [taylor]: Taking taylor expansion of f in f
0.356 * [taylor]: Taking taylor expansion of (/ 1 n) in f
0.356 * [taylor]: Taking taylor expansion of n in f
0.356 * [taylor]: Taking taylor expansion of (- (/ 1 f) (/ 1 n)) in f
0.356 * [taylor]: Taking taylor expansion of (/ 1 f) in f
0.356 * [taylor]: Taking taylor expansion of f in f
0.356 * [taylor]: Taking taylor expansion of (/ 1 n) in f
0.356 * [taylor]: Taking taylor expansion of n in f
0.357 * [taylor]: Taking taylor expansion of (* -1 (/ (+ (/ 1 f) (/ 1 n)) (- (/ 1 f) (/ 1 n)))) in f
0.357 * [taylor]: Taking taylor expansion of -1 in f
0.357 * [taylor]: Taking taylor expansion of (/ (+ (/ 1 f) (/ 1 n)) (- (/ 1 f) (/ 1 n))) in f
0.357 * [taylor]: Taking taylor expansion of (+ (/ 1 f) (/ 1 n)) in f
0.357 * [taylor]: Taking taylor expansion of (/ 1 f) in f
0.357 * [taylor]: Taking taylor expansion of f in f
0.357 * [taylor]: Taking taylor expansion of (/ 1 n) in f
0.357 * [taylor]: Taking taylor expansion of n in f
0.357 * [taylor]: Taking taylor expansion of (- (/ 1 f) (/ 1 n)) in f
0.357 * [taylor]: Taking taylor expansion of (/ 1 f) in f
0.357 * [taylor]: Taking taylor expansion of f in f
0.357 * [taylor]: Taking taylor expansion of (/ 1 n) in f
0.357 * [taylor]: Taking taylor expansion of n in f
0.358 * [taylor]: Taking taylor expansion of -1 in n
0.360 * [taylor]: Taking taylor expansion of (- (* 2 (/ 1 n))) in n
0.360 * [taylor]: Taking taylor expansion of (* 2 (/ 1 n)) in n
0.360 * [taylor]: Taking taylor expansion of 2 in n
0.360 * [taylor]: Taking taylor expansion of (/ 1 n) in n
0.360 * [taylor]: Taking taylor expansion of n in n
0.364 * [taylor]: Taking taylor expansion of (- (* 2 (/ 1 (pow n 2)))) in n
0.364 * [taylor]: Taking taylor expansion of (* 2 (/ 1 (pow n 2))) in n
0.364 * [taylor]: Taking taylor expansion of 2 in n
0.364 * [taylor]: Taking taylor expansion of (/ 1 (pow n 2)) in n
0.364 * [taylor]: Taking taylor expansion of (pow n 2) in n
0.364 * [taylor]: Taking taylor expansion of n in n
0.371 * [taylor]: Taking taylor expansion of (- (* 2 (/ 1 (pow n 3)))) in n
0.372 * [taylor]: Taking taylor expansion of (* 2 (/ 1 (pow n 3))) in n
0.372 * [taylor]: Taking taylor expansion of 2 in n
0.372 * [taylor]: Taking taylor expansion of (/ 1 (pow n 3)) in n
0.372 * [taylor]: Taking taylor expansion of (pow n 3) in n
0.372 * [taylor]: Taking taylor expansion of n in n
0.377 * [approximate]: Taking taylor expansion of (/ (+ (/ 1 f) (/ 1 n)) (- (/ 1 n) (/ 1 f))) in (f n) around 0
0.377 * [taylor]: Taking taylor expansion of (/ (+ (/ 1 f) (/ 1 n)) (- (/ 1 n) (/ 1 f))) in n
0.377 * [taylor]: Taking taylor expansion of (+ (/ 1 f) (/ 1 n)) in n
0.377 * [taylor]: Taking taylor expansion of (/ 1 f) in n
0.377 * [taylor]: Taking taylor expansion of f in n
0.377 * [taylor]: Taking taylor expansion of (/ 1 n) in n
0.377 * [taylor]: Taking taylor expansion of n in n
0.378 * [taylor]: Taking taylor expansion of (- (/ 1 n) (/ 1 f)) in n
0.378 * [taylor]: Taking taylor expansion of (/ 1 n) in n
0.378 * [taylor]: Taking taylor expansion of n in n
0.378 * [taylor]: Taking taylor expansion of (/ 1 f) in n
0.378 * [taylor]: Taking taylor expansion of f in n
0.379 * [taylor]: Taking taylor expansion of (/ (+ (/ 1 f) (/ 1 n)) (- (/ 1 n) (/ 1 f))) in f
0.379 * [taylor]: Taking taylor expansion of (+ (/ 1 f) (/ 1 n)) in f
0.379 * [taylor]: Taking taylor expansion of (/ 1 f) in f
0.379 * [taylor]: Taking taylor expansion of f in f
0.379 * [taylor]: Taking taylor expansion of (/ 1 n) in f
0.379 * [taylor]: Taking taylor expansion of n in f
0.379 * [taylor]: Taking taylor expansion of (- (/ 1 n) (/ 1 f)) in f
0.379 * [taylor]: Taking taylor expansion of (/ 1 n) in f
0.379 * [taylor]: Taking taylor expansion of n in f
0.379 * [taylor]: Taking taylor expansion of (/ 1 f) in f
0.379 * [taylor]: Taking taylor expansion of f in f
0.381 * [taylor]: Taking taylor expansion of (/ (+ (/ 1 f) (/ 1 n)) (- (/ 1 n) (/ 1 f))) in f
0.381 * [taylor]: Taking taylor expansion of (+ (/ 1 f) (/ 1 n)) in f
0.381 * [taylor]: Taking taylor expansion of (/ 1 f) in f
0.381 * [taylor]: Taking taylor expansion of f in f
0.381 * [taylor]: Taking taylor expansion of (/ 1 n) in f
0.381 * [taylor]: Taking taylor expansion of n in f
0.381 * [taylor]: Taking taylor expansion of (- (/ 1 n) (/ 1 f)) in f
0.381 * [taylor]: Taking taylor expansion of (/ 1 n) in f
0.381 * [taylor]: Taking taylor expansion of n in f
0.381 * [taylor]: Taking taylor expansion of (/ 1 f) in f
0.381 * [taylor]: Taking taylor expansion of f in f
0.382 * [taylor]: Taking taylor expansion of -1 in n
0.384 * [taylor]: Taking taylor expansion of (- (* 2 (/ 1 n))) in n
0.384 * [taylor]: Taking taylor expansion of (* 2 (/ 1 n)) in n
0.384 * [taylor]: Taking taylor expansion of 2 in n
0.384 * [taylor]: Taking taylor expansion of (/ 1 n) in n
0.384 * [taylor]: Taking taylor expansion of n in n
0.387 * [taylor]: Taking taylor expansion of (- (* 2 (/ 1 (pow n 2)))) in n
0.387 * [taylor]: Taking taylor expansion of (* 2 (/ 1 (pow n 2))) in n
0.387 * [taylor]: Taking taylor expansion of 2 in n
0.387 * [taylor]: Taking taylor expansion of (/ 1 (pow n 2)) in n
0.387 * [taylor]: Taking taylor expansion of (pow n 2) in n
0.387 * [taylor]: Taking taylor expansion of n in n
0.395 * [taylor]: Taking taylor expansion of (- (* 2 (/ 1 (pow n 3)))) in n
0.395 * [taylor]: Taking taylor expansion of (* 2 (/ 1 (pow n 3))) in n
0.395 * [taylor]: Taking taylor expansion of 2 in n
0.395 * [taylor]: Taking taylor expansion of (/ 1 (pow n 3)) in n
0.395 * [taylor]: Taking taylor expansion of (pow n 3) in n
0.395 * [taylor]: Taking taylor expansion of n in n
0.401 * * * [progress]: simplifying candidates
0.402 * [simplify]: Simplifying using  #<procedure:simplify-batch-regraph> :
   (- (log (- (+ f n))) (log (- f n)))
  (log (/ (- (+ f n)) (- f n)))
  (exp (/ (- (+ f n)) (- f n)))
  (/ (* (* (- (+ f n)) (- (+ f n))) (- (+ f n))) (* (* (- f n) (- f n)) (- f n)))
  (* (cbrt (/ (- (+ f n)) (- f n))) (cbrt (/ (- (+ f n)) (- f n))))
  (cbrt (/ (- (+ f n)) (- f n)))
  (* (* (/ (- (+ f n)) (- f n)) (/ (- (+ f n)) (- f n))) (/ (- (+ f n)) (- f n)))
  (sqrt (/ (- (+ f n)) (- f n)))
  (sqrt (/ (- (+ f n)) (- f n)))
  (- (- (+ f n)))
  (- (- f n))
  (/ 0 (- f n))
  (/ (+ f n) (- f n))
  (/ (* (cbrt (- (+ f n))) (cbrt (- (+ f n)))) (* (cbrt (- f n)) (cbrt (- f n))))
  (/ (cbrt (- (+ f n))) (cbrt (- f n)))
  (/ (* (cbrt (- (+ f n))) (cbrt (- (+ f n)))) (sqrt (- f n)))
  (/ (cbrt (- (+ f n))) (sqrt (- f n)))
  (/ (* (cbrt (- (+ f n))) (cbrt (- (+ f n)))) 1)
  (/ (cbrt (- (+ f n))) (- f n))
  (/ (* (cbrt (- (+ f n))) (cbrt (- (+ f n)))) (+ (sqrt f) (sqrt n)))
  (/ (cbrt (- (+ f n))) (- (sqrt f) (sqrt n)))
  (/ (* (cbrt (- (+ f n))) (cbrt (- (+ f n)))) 1)
  (/ (cbrt (- (+ f n))) (- f n))
  (/ (sqrt (- (+ f n))) (* (cbrt (- f n)) (cbrt (- f n))))
  (/ (sqrt (- (+ f n))) (cbrt (- f n)))
  (/ (sqrt (- (+ f n))) (sqrt (- f n)))
  (/ (sqrt (- (+ f n))) (sqrt (- f n)))
  (/ (sqrt (- (+ f n))) 1)
  (/ (sqrt (- (+ f n))) (- f n))
  (/ (sqrt (- (+ f n))) (+ (sqrt f) (sqrt n)))
  (/ (sqrt (- (+ f n))) (- (sqrt f) (sqrt n)))
  (/ (sqrt (- (+ f n))) 1)
  (/ (sqrt (- (+ f n))) (- f n))
  (/ 1 (* (cbrt (- f n)) (cbrt (- f n))))
  (/ (- (+ f n)) (cbrt (- f n)))
  (/ 1 (sqrt (- f n)))
  (/ (- (+ f n)) (sqrt (- f n)))
  (/ 1 1)
  (/ (- (+ f n)) (- f n))
  (/ 1 (+ (sqrt f) (sqrt n)))
  (/ (- (+ f n)) (- (sqrt f) (sqrt n)))
  (/ 1 1)
  (/ (- (+ f n)) (- f n))
  (/ -1 (* (cbrt (- f n)) (cbrt (- f n))))
  (/ (+ f n) (cbrt (- f n)))
  (/ -1 (sqrt (- f n)))
  (/ (+ f n) (sqrt (- f n)))
  (/ -1 1)
  (/ (+ f n) (- f n))
  (/ -1 (+ (sqrt f) (sqrt n)))
  (/ (+ f n) (- (sqrt f) (sqrt n)))
  (/ -1 1)
  (/ (+ f n) (- f n))
  (/ (- (* (cbrt (+ f n)) (cbrt (+ f n)))) (* (cbrt (- f n)) (cbrt (- f n))))
  (/ (cbrt (+ f n)) (cbrt (- f n)))
  (/ (- (* (cbrt (+ f n)) (cbrt (+ f n)))) (sqrt (- f n)))
  (/ (cbrt (+ f n)) (sqrt (- f n)))
  (/ (- (* (cbrt (+ f n)) (cbrt (+ f n)))) 1)
  (/ (cbrt (+ f n)) (- f n))
  (/ (- (* (cbrt (+ f n)) (cbrt (+ f n)))) (+ (sqrt f) (sqrt n)))
  (/ (cbrt (+ f n)) (- (sqrt f) (sqrt n)))
  (/ (- (* (cbrt (+ f n)) (cbrt (+ f n)))) 1)
  (/ (cbrt (+ f n)) (- f n))
  (/ (- (sqrt (+ f n))) (* (cbrt (- f n)) (cbrt (- f n))))
  (/ (sqrt (+ f n)) (cbrt (- f n)))
  (/ (- (sqrt (+ f n))) (sqrt (- f n)))
  (/ (sqrt (+ f n)) (sqrt (- f n)))
  (/ (- (sqrt (+ f n))) 1)
  (/ (sqrt (+ f n)) (- f n))
  (/ (- (sqrt (+ f n))) (+ (sqrt f) (sqrt n)))
  (/ (sqrt (+ f n)) (- (sqrt f) (sqrt n)))
  (/ (- (sqrt (+ f n))) 1)
  (/ (sqrt (+ f n)) (- f n))
  (/ (- 1) (* (cbrt (- f n)) (cbrt (- f n))))
  (/ (+ f n) (cbrt (- f n)))
  (/ (- 1) (sqrt (- f n)))
  (/ (+ f n) (sqrt (- f n)))
  (/ (- 1) 1)
  (/ (+ f n) (- f n))
  (/ (- 1) (+ (sqrt f) (sqrt n)))
  (/ (+ f n) (- (sqrt f) (sqrt n)))
  (/ (- 1) 1)
  (/ (+ f n) (- f n))
  (/ (- 1) (* (cbrt (- f n)) (cbrt (- f n))))
  (/ (+ f n) (cbrt (- f n)))
  (/ (- 1) (sqrt (- f n)))
  (/ (+ f n) (sqrt (- f n)))
  (/ (- 1) 1)
  (/ (+ f n) (- f n))
  (/ (- 1) (+ (sqrt f) (sqrt n)))
  (/ (+ f n) (- (sqrt f) (sqrt n)))
  (/ (- 1) 1)
  (/ (+ f n) (- f n))
  (/ (* (cbrt (+ f n)) (cbrt (+ f n))) (* (cbrt (- f n)) (cbrt (- f n))))
  (/ (- (cbrt (+ f n))) (cbrt (- f n)))
  (/ (* (cbrt (+ f n)) (cbrt (+ f n))) (sqrt (- f n)))
  (/ (- (cbrt (+ f n))) (sqrt (- f n)))
  (/ (* (cbrt (+ f n)) (cbrt (+ f n))) 1)
  (/ (- (cbrt (+ f n))) (- f n))
  (/ (* (cbrt (+ f n)) (cbrt (+ f n))) (+ (sqrt f) (sqrt n)))
  (/ (- (cbrt (+ f n))) (- (sqrt f) (sqrt n)))
  (/ (* (cbrt (+ f n)) (cbrt (+ f n))) 1)
  (/ (- (cbrt (+ f n))) (- f n))
  (/ (sqrt (+ f n)) (* (cbrt (- f n)) (cbrt (- f n))))
  (/ (- (sqrt (+ f n))) (cbrt (- f n)))
  (/ (sqrt (+ f n)) (sqrt (- f n)))
  (/ (- (sqrt (+ f n))) (sqrt (- f n)))
  (/ (sqrt (+ f n)) 1)
  (/ (- (sqrt (+ f n))) (- f n))
  (/ (sqrt (+ f n)) (+ (sqrt f) (sqrt n)))
  (/ (- (sqrt (+ f n))) (- (sqrt f) (sqrt n)))
  (/ (sqrt (+ f n)) 1)
  (/ (- (sqrt (+ f n))) (- f n))
  (/ 1 (* (cbrt (- f n)) (cbrt (- f n))))
  (/ (- (+ f n)) (cbrt (- f n)))
  (/ 1 (sqrt (- f n)))
  (/ (- (+ f n)) (sqrt (- f n)))
  (/ 1 1)
  (/ (- (+ f n)) (- f n))
  (/ 1 (+ (sqrt f) (sqrt n)))
  (/ (- (+ f n)) (- (sqrt f) (sqrt n)))
  (/ 1 1)
  (/ (- (+ f n)) (- f n))
  (/ 1 (* (cbrt (- f n)) (cbrt (- f n))))
  (/ (- (+ f n)) (cbrt (- f n)))
  (/ 1 (sqrt (- f n)))
  (/ (- (+ f n)) (sqrt (- f n)))
  (/ 1 1)
  (/ (- (+ f n)) (- f n))
  (/ 1 (+ (sqrt f) (sqrt n)))
  (/ (- (+ f n)) (- (sqrt f) (sqrt n)))
  (/ 1 1)
  (/ (- (+ f n)) (- f n))
  (/ 1 (- f n))
  (/ (- f n) (- (+ f n)))
  (/ (+ f n) (- f n))
  (/ (- (+ f n)) (* (cbrt (- f n)) (cbrt (- f n))))
  (/ (- (+ f n)) (sqrt (- f n)))
  (/ (- (+ f n)) 1)
  (/ (- (+ f n)) (+ (sqrt f) (sqrt n)))
  (/ (- (+ f n)) 1)
  (/ (- f n) (cbrt (- (+ f n))))
  (/ (- f n) (sqrt (- (+ f n))))
  (/ (- f n) (- (+ f n)))
  (/ (- f n) (+ f n))
  (/ (- f n) (cbrt (+ f n)))
  (/ (- f n) (sqrt (+ f n)))
  (/ (- f n) (+ f n))
  (/ (- f n) (+ f n))
  (/ (- f n) (- (cbrt (+ f n))))
  (/ (- f n) (- (sqrt (+ f n))))
  (/ (- f n) (- (+ f n)))
  (/ (- f n) (- (+ f n)))
  (/ (- (+ f n)) (- (pow f 3) (pow n 3)))
  (/ (- (+ f n)) (- (* f f) (* n n)))
  (* (- f n) (+ (* f f) (- (* n n) (* f n))))
  (* (- f n) (- f n))
  1
  -1
  -1
0.406 * * [simplify]: iteration  0 :  133  enodes  (cost  1451 )
0.431 * * [simplify]: iteration  1 :  293  enodes  (cost  1378 )
0.479 * * [simplify]: iteration  2 :  819  enodes  (cost  1348 )