two questions about simple diagram

Question

\documentclass{amsart}
\usepackage{tikz-cd}

\begin{document}

\begin{tikzpicture}[baseline= (a).base][>=stealth,>=implies]
\node[scale=1.4] (a) at (0,0){
\begin{tikzcd}
    \text{(a)}  \rar[Leftrightarrow]  
    & [1.8em] \text{(b)}  
    & [2em]  \text{(c)}\lar[Leftarrow]\arrow[ddl,Rightarrow]\footnotesize\text{(i,ii, or iii)}\\
    & \vspace{-5mm}  \\&\text{\hspace{1mm}(b)$^\prime$}\arrow[uu,Leftrightarrow] 
    \end{tikzcd}
};
\end{tikzpicture}

\end{document}

produces this:

Questions:

(1) How can I make the diagonal arrow start at (c), as it normally would without "(i,ii, or iii)"?

(2) The arrow from (b) to (c) needs a line through the center, similar to what $\centernot\implies$ produces:

(1) A dirty solution could be add & \hspace{-3em} before of "(i,ii, or iii)" — Fran, May 31 '17 at 06:36
@Fran that works perfectly! Now I just need an answer to (2) — Forever Mozart, May 31 '17 at 06:45
@Fran For (1) I think \arrow[ddl,Rightarrow,start anchor=south west] is better. (I'm working on the second point). — CarLaTeX, May 31 '17 at 06:52
@CarLaTeX Sure, that's why I said "dirty" (I have little memory for the right anchor tikz syntax, and I did not have time to search it). BTW,+1 — Fran, May 31 '17 at 07:25
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CarLaTeX · Answer 1 · 2017-05-31T13:10:02.773

This is what I suggest to you:

use start anchor=south west option
put a / on the arrow (as a "fake" label, edit: egreg's answer make me realize that a simple / is enough, instead of an inverted \backslash as in my previous version).

By the way: why are you nesting a tikzcd (which is a tikzpicture) within another tikzpicture?

\documentclass{amsart}
\usepackage{tikz-cd}

\begin{document}

    \begin{tikzcd}
        \text{(a)}  \rar[Leftrightarrow]  
        & [1.8em] \text{(b)}  
        & [2em]  \text{(c)\footnotesize(i,ii, or iii)}\arrow[l, Leftarrow, "/" {yshift=7pt, scale=1.2}]
        \arrow[ddl,Rightarrow,start anchor=south west]\\
        & \vspace{-5mm}  \\&\text{\hspace{1mm}(b)$^\prime$}\arrow[uu,Leftrightarrow] 
    \end{tikzcd}

\end{document}

Output:

score 4 · Answer 2 · answered May 31 '17 at 11:05

You can use this answer by Percusse for the negated arrow:

\documentclass{amsart}
\usepackage{tikz-cd}
\usetikzlibrary{decorations.markings}
% https://tex.stackexchange.com/a/51024/
\tikzset{
  negated/.style={
    decoration={
      markings,
      mark=at position 0.5 with {\node[transform shape] (tempnode) {$/$};},
    },
    postaction={decorate},
  },
}
\begin{document}

\begin{tikzcd}[column sep=4em,row sep=4em,inner xsep=0pt]
\text{(a)} \arrow[r,Leftrightarrow] &
\text{(b)} \arrow[d,Leftrightarrow] \arrow[r,Rightarrow,negated] &
\text{(c) (i, ii, or iii)} \arrow[dl,Rightarrow,start anchor=south west] \\
& \text{(b)\makebox[0pt][l]{$'$}} % no width for the prime
\end{tikzcd}

\end{document}

Sometimes the simplest solution doesn't come to mind. I thought of \not (which didn't work well) but not of /. — CarLaTeX, May 31 '17 at 12:30
Thanks @CarLaTeX and egreg. Now my only problem is deciding which to use... — Forever Mozart, May 31 '17 at 21:26

two questions about simple diagram

2 Answers2