I am trying to write the following composition of epimorphisms, but I don't like the form.
The code is:
\documentclass[12pt,a4paper]{book}
\usepackage[utf8]{inputenc}
\usepackage[english,greek]{babel}
\usepackage{amsmath,amsfonts,amssymb}
\newcommand{\rightarrowdbl}{\rightarrow\mathrel{\mkern-14mu}\rightarrow}
\newcommand{\xrightarrowdbl}[2][]{%
\xrightarrow[#1]{#2}\mathrel{\mkern-14mu}\rightarrow}
\begin{document}
\begin{align*}
\phi \circ \pi: \mathbb{Z}[X] & \xrightarrowdbl{\ \pi \ } \mathbb{Z}_2[X] && \xrightarrowdbl{\ \phi \ } \mathbb{Z}_2,\\
f(X) & \longmapsto \pi (f(X)):=\overline{f(X)} && \longmapsto \phi(\overline{f(X)}):=\overline{f(0)}
\end{align*}
\end{document}
Is there a better way to write it?
Thank you!
:=
with\mathrel{\mathop:}=
. What exactly are you interested in changing? Thank you. – Sebastiano Feb 12 '19 at 13:20tikz-cd
orxy
and the translator (now no :-(), – Sebastiano Feb 12 '19 at 16:42\overline{f(X)}
and\longmapsto
by using\begin{alignat*}{2}
instead of\begin{align*}
(and the corresponding end). But it's bad nonetheless. – egreg Feb 12 '19 at 17:07