English: Diagram of the fundamental theorem on homomorphisms where f is an homomorphism, N is a normal subgroup of G and e is the identity element of G. Created with Inkscape. PNG version at: https://commons.wikimedia.org/wiki/File:PNG_diagram_of_the_fundamental_theorem_on_homomorphisms.png because original arrows were broken, but this was later fixed. My tutorial on the subject at: https://math.stackexchange.com/questions/776039/intuition-behind-normal-subgroups/3732426#3732426.