:: deftheorem Def08b defines -harmonique MUSIC_S1:def 19 :
for S being satisfying_equiv satisfying_interval satisfying_Nat satisfying_harmonic_closed MusicStruct
for frequency being Element of S
for n being non zero Nat
for b₄ being Element of S holds
( b₄ = n -harmonique (S,frequency) iff [frequency,b₄] in Class ( the Equidistance of S,[1,n]) );