nnss 見易い式を求めて
次の不等式を簡約します.
(%i86) f:(x^2-1)*(x^2-4)*(x^2-9)<0; Evaluation took 0.0000 seconds (0.0000 elapsed) using 1.344 KB. (%o86) (x^2-9)*(x^2-4)*(x^2-1) < 0
まずは,qepmax + nns です.悪くはありませんが,ちょっと解り難いですね.
(%i87) qe([],f); Evaluation took 0.1000 seconds (0.3300 elapsed) using 2.794 MB. (%o87) (x-3 < 0) %and (x-2 # 0) %and (x-1 # 0) %and (x+1 # 0) %and (x+2 # 0) %and (x+3 > 0) %and ((x-2 > 0) %or (x+2 < 0) %or ((x-1 < 0) %and (x+1 > 0))) (%i88) nns(%); Evaluation took 4.9000 seconds (6.1500 elapsed) using 232.032 MB. (%o88) (x-3 < 0) %and (x+3 > 0) %and ((x-2 > 0) %or (x+2 < 0) %or ((x-1 < 0) %and (x+1 > 0)))
ということで,nnss の出番です.
(%i89) nnss(f); Evaluation took 4.4000 seconds (7.2900 elapsed) using 194.955 MB. (%o89) ((x-3 < 0) %and (x-2 > 0)) %or ((x-1 < 0) %and (x+1 > 0)) %or ((x+2 < 0) %and (x+3 > 0))