Correction ((4)) : « ∫ 0 ϖ Cos . p x . Sin . q x Sin . x = {\displaystyle \int _{0}^{\varpi }{\frac {\operatorname {Cos} .px.\operatorname {Sin} .qx}{\operatorname {Sin} .x}}=} » → « ∫ 0 ϖ Cos . p x . Sin . q x Sin . x d x = {\displaystyle \int _{0}^{\varpi }{\frac {\operatorname {Cos} .px.\operatorname {Sin} .qx}{\operatorname {Sin} .x}}\operatorname {d} x=} » (coquille)