begin{figure*}
centering
subfloat[][]{
    label{fig:ex1}
    begin{tikzpicture}[baseline=(a1.base),->,>=stealth',shorten >=1pt,auto,node distance=1.24cm, main node/.style={circle,draw, minimum size=1em}]
    node[main node] (a1) {small $n_1$};
    node[main node] (a2) [below left of=a1] {small $n_2$};
    node[main node] (a3) [below right of=a1] {small $n_3$};
    path (a1) edge [] node {} (a3)
    (a1) edge [] node {} (a2);
    end{tikzpicture}
}
quad
centering
subfloat[][]{
    label{fig:ex2}
    begin{tikzpicture}[baseline=(b1.base),->,>=stealth',shorten >=1pt,auto,node distance=1.24cm, main node/.style={circle,draw}]
    node[main node] (b1) {small $n_1$};
    node[main node] (b2) [below left of=b1] {small $n_2$};
    node[main node] (b3) [below right of=b1] {small $n_3$};
    path
    (b1) edge [] node {} (b3)
    (b1) edge [] node {} (b2)
    (b3) edge [in=45,out=315, looseness=1.5] node {} (b1);
    end{tikzpicture}
}
quad
centering
subfloat[][]{
    label{fig:ex3}
    begin{tikzpicture}[baseline=(c1.base),->,>=stealth',shorten >=1pt,auto,node distance=1.24cm, main node/.style={circle,draw}]
    node[main node] (c1) {small $n_1$};
    node[main node] (c2) [below left of=c1] {small $n_2$};
    node[main node] (c3) [below right of=c1] {small $n_3$};
    path
    (c1) edge [] node {} (c3)
    (c1) edge [] node {} (c2)
    (c3) edge [in=-45,out=315, looseness=1.5] node {} (c2);
    end{tikzpicture}
}
quad
centering
subfloat[][]{
    label{fig:ex4}
    begin{tikzpicture}[baseline=(d1.base),->,>=stealth',shorten >=1pt,auto,node distance=1.24cm, main node/.style={circle,draw}]
    node[main node] (d1) {small $n_1$};
    node[main node] (d2) [below left of=d1] {small $n_2$};
    node[main node] (d3) [below right of=d1] {small $n_3$};
    path
    (d1) edge [] node {} (d3)
    (d1) edge [] node {} (d2)
    (d3) edge [in=45,out=315,loop] node {} (d3);
    end{tikzpicture}
}
quad
centering
subfloat[][]{
    label{fig:ex5}
    begin{tikzpicture}[baseline=(e1.base),->,>=stealth',shorten >=1pt,auto,node distance=1.24cm, main node/.style={circle,draw}]
    node[main node] (e1) {small $n_1$};
    node[main node] (e2) [below left of=e1] {small $n_2$};
    node[main node] (e3) [below right of=e1] {small $n_3$};
    node[main node, dashed] (e4) [below right of=e3] {small $n_4$};
    path
    (e1) edge [] node {} (e3)
    (e1) edge [] node {} (e2)
    (e3) edge [in=135,out=315] node {} (e4);
    end{tikzpicture}
}
caption{Steps in Korat exploration to find an extendable candidate vector}
end{figure*}