theorem
proved
tetStep_jcost_pos
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IndisputableMonolith.MusicTheory.TuningSystemJCostRanking on GitHub at line 75.
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depends on
-
Jcost_pos_of_ne_one -
Jcost_pos_of_ne_one -
cost -
cost -
beats -
beats -
Jcost_pos_of_ne_one -
Cost -
stepCost -
tetStep -
tetStep_band
used by
formal source
72 norm_num
73
74/-- 12-TET step J-cost > 0. -/
75theorem tetStep_jcost_pos : 0 < stepCost tetStep := by
76 apply Cost.Jcost_pos_of_ne_one tetStep
77 · have := tetStep_band.1; linarith
78 · intro h; have := tetStep_band.1; linarith
79
80/-- JI beats 12-TET (JI J-cost < 12-TET J-cost). -/
81theorem ji_beats_tet : jiCost < stepCost tetStep := by
82 rw [jiCost_zero]
83 exact tetStep_jcost_pos
84
85structure TuningRankingCert where
86 ji_zero : jiCost = 0
87 tet_positive : 0 < stepCost tetStep
88 ji_beats_tet : jiCost < stepCost tetStep
89
90/-- Tuning-system J-cost ranking certificate. -/
91def tuningRankingCert : TuningRankingCert where
92 ji_zero := jiCost_zero
93 tet_positive := tetStep_jcost_pos
94 ji_beats_tet := ji_beats_tet
95
96end
97end TuningSystemJCostRanking
98end MusicTheory
99end IndisputableMonolith