Mdthbs

I'm trying to reproduce a structure like this:

But all I could come up with was the following code:

begin{table}[!htb]

    caption{Global caption}

    begin{minipage}{.5linewidth}

        caption*{$G$}

        centering

                begin{tabular}{|c|c|lll}

                    cline{1-2}

                    textbf{Vertex} & textbf{Label}\ cline{1-2}

                    b               & 1             \

                    c               & 1             \

                    d               & 1             \ cline{1-2}

                end{tabular}

    end{minipage}%

    begin{minipage}{.5linewidth}

        centering

        caption*{$F$}

                begin{tabular}{|c|c|lll}

                    cline{1-2}

                    textbf{Vertex} & textbf{Label}\ cline{1-2}

                    b               & 1             \

                    c               & 1             \

                    d               & 1             \ cline{1-2}

                end{tabular}

    end{minipage} 

end{table}



begin{table}[!htb]

    caption*{Global caption}

    begin{minipage}{.5linewidth}

        caption*{$G$}

        centering

        begin{tabular}{|c|c|lll}

            cline{1-2}

            textbf{Vertex} & textbf{Label}\ cline{1-2}

            b               & 1             \

            c               & 1             \

            d               & 1             \ cline{1-2}

        end{tabular}

    end{minipage}%

    begin{minipage}{.5linewidth}

        centering

        caption*{$F$}

        begin{tabular}{|c|c|lll}

            cline{1-2}

            textbf{Vertex} & textbf{Label}\ cline{1-2}

            b               & 1             \

            c               & 1             \

            d               & 1             \ cline{1-2}

        end{tabular}

    end{minipage} 

end{table}



begin{table}[!htb]

    caption*{Global caption}

    begin{minipage}{.5linewidth}

        caption*{$G$}

        centering

        begin{tabular}{|c|c|lll}

            cline{1-2}

            textbf{Vertex} & textbf{Label}\ cline{1-2}

            b               & 1             \

            c               & 1             \

            d               & 1             \ cline{1-2}

        end{tabular}

    end{minipage}%

    begin{minipage}{.5linewidth}

        centering

        caption*{$F$}

        begin{tabular}{|c|c|lll}

            cline{1-2}

            textbf{Vertex} & textbf{Label}\ cline{1-2}

            b               & 1             \

            c               & 1             \

            d               & 1             \ cline{1-2}

        end{tabular}

    end{minipage} 

end{table}

which somewhat resembles the structure, but keeps my tables way too much separated from each other. Can anyone suggest me a better way to obtain the desired results?

Thank you in advance.

It is also possible to build these tabulars using cals and one calstable. By defining shortcuts for removing cell border, it is convinient to remove the necessary borders around the cells. Of cause, sub-labels are ordinary text, so it is not possible to refer to subtable 1(c). If you prefer more narrow table, just increase the the divisor when calculating the column width.

documentclass{article}

usepackage{cals, caption}



letnc=nullcell                        % Shortcuts

letsc=spancontent



begin{document}



begin{table}[ht]



begin{calstable}[c] % Centre the tabular



% Defining columns relative to the margin 

colwidths{{dimexpr(columnwidth)/5relax}  % Increase 5 to 6 or 7 to make the tabular more narrow 

            {dimexpr(columnwidth)/5relax}

            {dimexpr(columnwidth)/5relax}

            {dimexpr(columnwidth)/5relax}

            {dimexpr(columnwidth)/5relax}

            }



% Set up the tabular

makeatletter

defcals@framers@width{0.4pt}   % Outside frame rules, reduce if the rule is too heavy

defcals@framecs@width{0.4pt}

defcals@bodyrs@width{0.4pt}

defcals@cs@width{0.4pt}             % Inside rules, reduce if the rule is too heavy

defcals@rs@width{0.4pt}



deftb{ifxcals@borderTrelax     % Top border switch (off-on)

    defcals@borderT{0pt}

else letcals@borderTrelaxfi}



defbb{ifxcals@borderBrelax     % Botton border switch (off-on)

    defcals@borderB{0pt}

else letcals@borderBrelaxfi}



defrb{ifxcals@borderRrelax     % Right border switch (off-on)

    defcals@borderR{0pt}

else letcals@borderRrelaxfi}



deflb{ifxcals@borderLrelax     % Left border switch (off-on)

    defcals@borderL{0pt}

else letcals@borderLrelaxfi}





% R1H1

brow

    lbtbrbalignCnc{ltb}

    nc{rtb}sc{$G$}

    bbcell{}bb

    nc{ltb}

    nc{rtb}sc{$H$}lbtbrb

erow

% R2B1

brow

    cell{Vertex}

    cell{Label}

    bbcell{}bb

    cell{Vertex}

    cell{Label}

erow

% R3B2

brow

    cell{b}

    cell{1}

    bbcell{}bb

    cell{c}

    cell{1}

erow

% R4B3

brow

    cell{c}

    cell{1}

    bbcell{}bb

    cell{a}

    cell{1}

erow

% R5B4

brow

    cell{d}

    cell{1}

    bbcell{}bb

    cell{d}

    cell{1}

erow

% R6B5

brow

    lbrbnc{ltb}

    nc{tb}

    nc{tb}

    nc{tb}

    nc{rtb}sc{(a)}lbrb

erow

% R7B6

brow

    lbtbrbalignCnc{ltb}

    nc{rtb}sc{$G$}

    bbcell{}bb

    nc{ltb}

    nc{rtb}sc{$H$}lbtbrb

erow

% R8B7

brow

    cell{Vertex}

    cell{Label}

    bbcell{}bb

    cell{Vertex}

    cell{Label}

erow

% R9B8

brow

    cell{c}

    cell{11}

    bbcell{}bb

    cell{a}

    cell{11}

erow

% R10B9

brow

    cell{d}

    cell{10}

    bbcell{}bb

    cell{d}

    cell{11}

erow

% R11B10

brow

    rblbnc{ltb}

    nc{tb}

    nc{tb}

    nc{tb}

    nc{rtb}sc{(b)}rblb

erow

% R12B11

brow

    lbtbrbalignCnc{ltb}

    nc{rtb}sc{$G$}

    bbcell{}bb

    nc{ltb}

    nc{rtb}sc{$H$}lbtbrb

erow

% R13B12

brow

    cell{Vertex}

    cell{Label}

    bbcell{}bb

    cell{Vertex}

    cell{Label}

erow

% R14B13

brow

    cell{d}

    cell{101}

    bbcell{}bb

    cell{d}

    cell{101}

erow

% R15B14

brow

    lbrbbbnc{ltb}

    nc{tb}

    nc{tb}

    nc{tb}

    nc{rtb}sc{(c)}lbrbbb

erow

makeatletter

end{calstable}par % par to align the tabular



caption{Labels on the non-mapped vertices of $G$ and $H$ with mapping: Fig (a) $M={a,b}$, Fig. (b) $M={ab,bc}$, and (c) $M={abc, bca}$}

end{table}



end{document}

I suggest you load the subcaption package, which provides an environment called subtable. To (more or less) replicate the structure shown in the screenshot you posted, you could set up three subtable environments, each with its own caption, inside the overall table environment. In the code below, each subtable contains two tabular environments.

documentclass{article} % or some other, more suitable document class

usepackage{array} % for 'extrarowheight' macro

usepackage{subcaption} % for 'subtable' environment

begin{document}



begin{table}[!htb]

setlength{extrarowheight}{1pt} % for a more open "look"



centering



begin{subtable}{.55linewidth} % choose width suitably

begin{tabular}{|c|c|} % 1st tabular

multicolumn{2}{c}{$G$}\

hline

Vertex & Label\ 

hline

b & 1 \

c & 1 \

d & 1 \ hline

end{tabular}%

hfill % maximize distance between adjacent tabulars

begin{tabular}{|c|c|} % 2nd tabular

multicolumn{2}{c}{$H$}\

hline

Vertex & Label\ 

hline

c & 1 \

a & 1 \

d & 1 \ hline

end{tabular}



smallskip

caption{$M={a,b}$}

end{subtable}



vspace{5mm} % insert a bit of vertical whitespace

begin{subtable}{.55linewidth}

begin{tabular}{|c|c|}

multicolumn{2}{c}{$G$}\

hline

Vertex & Label\ 

hline

c & 11 \

d & 10 \ hline

end{tabular}%

hfill

begin{tabular}{|c|c|}

multicolumn{2}{c}{$H$}\

hline

Vertex & Label\ 

hline

a & 11 \

d & 11 \ hline

end{tabular}



smallskip

caption{$M={ab,bc}$}

end{subtable}



vspace{5mm}

begin{subtable}{.55linewidth}

begin{tabular}{|c|c|}

multicolumn{2}{c}{$G$}\

hline

Vertex & Label\ 

hline

d & 101 \ hline

end{tabular}%

hfill

begin{tabular}{|c|c|}

multicolumn{2}{c}{$H$}\

hline

Vertex & Label\ 

hline

d & 110 \ hline

end{tabular}



smallskip

caption{$M={abc,bca}$}

end{subtable}



caption{Labels on the non-mapped vertices of $G$ and $H$, for selected choices of mapping $M$}

end{table}

end{document}