Further comment on another hybrid conjugate gradient algorithm for unconstrained optimization by Andrei

In Dai and Wen (Numer. Algor. 69 , 337–341 2015 ), some improvements have been presented in the proof of Theorem 2 and Theorem 4 in Andrei (Numer. Algor. 47 , 143–156 2008 ). However, due to incorrect inequalities used, the reasoning proof of Theorem 2.1 in Dai and Wen (Numer. Algor. 69 , 337–341 2015 ) is incorrect. Moreover, the assumption on 0 < c 1 ≤ 𝜃 k < 1 of Theorem 2.1 cannot be deleted in Dai and Wen (Numer. Algor. 69 , 337–341 2015 ). In this paper, the necessary corrections are made. Finally, another version of the proof process of Theorem 3.1 in (Numer. Algor. 69 , 337–341 2015 ) is given. Throughout, we use the same notations and equation numbers as in Dai and Wen (Numer. Algor. 69 , 337–341 2015 ), Andrei (Numer. Algor. 47 , 143–156 2008 ).