Read More
Date: 21-6-2017
![]()
Date: 2-7-2017
![]()
Date: 26-6-2021
![]() |
A diagram lemma which states that, given the above commutative diagram with exact rows, the following holds:
1. If is surjective, and
and
are injective, then
is injective;
2. If is injective, and
and
are surjective, then
is surjective.
This lemma is closely related to the five lemma, which is based on a similar diagram obtained by adding a single column.
REFERENCES:
Mac Lane, S. Homology. Berlin: Springer-Verlag, p. 364, 1967.
|
|
دراسة: عدم ترتيب الغرفة قد يدل على مشاكل نفسية
|
|
|
|
|
علماء: تغير المناخ تسبب في ارتفاع الحرارة خلال موسم الحج
|
|
|
|
|
شعبة فاطمة بنت أسد للدراسات القرآنية تختتم دورة ينابيع الرحمة
|
|
|