Also known as the Eckmann–Shapiro Lemma, Shapiro's lemma is useful in numerous areas of the abstract algebra field in mathematics. In the 21st century, Beno Eckmann and Arnold Shapiro individually contributed to the realization of this concept, which relates extensions of modules over one ring to extensions over another. This especially works best in the group ring of a group and of a subgroup.
Eckmann Lemma
Eckmann—Shapiro Lemma
Erick—Shapiro Lemma
Erick Lemma
Arnold Shapiro
Alfred Shapiro
Josh Shapiro
Matt Shapiro
1961
1962
1963
1964
Beno Erick
Alfred Eckmann
Beno Eckmann
Alfred Erick
1951
1952
1953
1954
Ring homomorphism
Ring endomorphism
Ring
Ring and Satellite
Right S-module
Left S-module
Left M-module
Right M-module
Left R-module
Right R-module
Left N-module
Right N-module
Left and right S-module
Left and right R-module
Left and right M-module
Left and right N-module
Group of modules
Radius
Ring
Group ring