TikZ and PGF Manual
Part II Installation and Configuration
by Till Tantau
This part explains how the system is installed. Typically, someone has already done so for your system, so this part can be skipped; but if this is not the case and you are the poor fellow who has to do the installation, read the present part.
\usetikzlibrary {arrows.meta,automata,positioning,shadows}
\begin{tikzpicture}[->,>={Stealth[round]},shorten >=1pt,auto,node distance=2.8cm,on grid,semithick,
every state/.style={fill=red,draw=none,circular drop shadow,text=white}]
\node[initial,state] (A) {$q_a$};
\node[state] (B) [above right=of A] {$q_b$};
\node[state] (D) [below right=of A] {$q_d$};
\node[state] (C) [below right=of B] {$q_c$};
\node[state] (E) [below=of D] {$q_e$};
\path (A) edge
node
{0,1,L} (B)
edge
node
{1,1,R} (C)
(B) edge [loop above] node {1,1,L} (B)
edge
node
{0,1,L} (C)
(C) edge
node
{0,1,L} (D)
edge
[bend left] node {1,0,R} (E)
(D) edge [loop below] node {1,1,R} (D)
edge
node
{0,1,R} (A)
(E) edge [bend left] node {1,0,R} (A);
\node [right=1cm,text width=8cm] at
(C)
{
The
current
candidate for
the busy
beaver for
five
states. It
is
presumed
that this
Turing machine
writes a
maximum number
of
$1$'s
before halting
among all
Turing machines
with five
states
and
the
tape
alphabet $\{0, 1\}$. Proving
this conjecture
is an
open
research
problem.
};
\end{tikzpicture}