semipositone adjective2 •an eigenvalue problem that would be a positone eigenvalue problem except that the nonlinear function is not positive when its argument is zero.Finally, we mention that several papers studied nonlinear eigenvalue problems of the form — 2004 •for scriptstyle λ>0 under the assumption that scriptstyle f: ℝ→ ℝ is continuous, positive, monotone. For this reason such problems were named positone... If the nonlinearity scriptstyle f: ℝ→ ℝ is continuous, monotone and scriptstyle f(0)<0,...then the eigenvalue problem is called semipositone...