International Journal of Mathematics and Mathematical Sciences
Volume 9 (1986), Issue 4, Pages 785-789
doi:10.1155/S0161171286000959
Abstract
Let g,f1,…,fm∈H∞(Δ). We provide conditions on f1,…,fm in order that |g(z)|≤|f1(z)|+…+|fm(z)|, for all z in Δ, imply that g, or g2, belong to the ideal generated by f1,…,fm in H∞.