When latex processes a Maple object of type function (i.e., an unevaluated function call), it checks to see if there exists a procedure by the name of latex/function_name, where function_name is the name of the function.  If such a procedure exists, it is used to format the function call.

For instance, invoking latex(Int(exp(x), x=1..3)) causes latex to check to see if there is a procedure by the name of latex/Int. Since such a procedure exists, the above call to latex returns the result of latex/Int(exp(x), x=1..3) as its value.  This allows LaTeX to produce standard mathematical output in most situations.

If such a procedure does not exist, latex formats the function call by recursively formatting the operands to the function call and inserting parentheses and commas at the appropriate points.

Maple has pre-defined latex/ functions for the following constructs:

Standard mathematical functions such as sin, cos, and tan are converted to  \sin,  \cos, and  \tan.  See latex/names for a description of how this is done.

$\mathrm{latex}\left(\mathrm{Int}\left(\exp \left(x\right)\,x\right)\right)$

\int \!{{\rm e}^{x}}\,{\rm d}x

$\mathrm{latex}\left(\mathrm{Limit}\left(3+y\left(x\right)\,x=0\,\mathrm{left}\right)\right)$

\lim _{x\rightarrow 0^{-}}3+y \left( x \right)

`latex/BesselJ` := proc(a,z)
    sprintf("{ {\\rm J}_{%s}(%s) }",cat("", `latex/print`(a)), cat("", `latex/print`(z)))
end proc:

$\mathrm{latex}\left(\mathrm{BesselJ}\left(n\,z+1\right)\right)$

{ {\rm J}_{n}(z+1) }

`latex/hypergeom` := proc(A0, B0, z0)
local nA, nB, pFq, p, q, A, B, z;

    nA, nB := nops(A0), nops(B0);
    pFq := cat('`\\mbox{$_`',nA,'`$F$_`',nB,'`$}`');
    if nA = 0 then A, nA := [`\\ `], 1 else A := map(u -> cat(`latex/print`(u)), A0) end if;
    if nB = 0 then B, nB := [`\\ `], 1 else B := map(u -> cat(`latex/print`(u)), B0) end if;
    z := cat(`latex/print`(z0));
    p := op(map(u -> (u, '`,`'), A[1 .. -2])), A[-1];
    q := op(map(u -> (u, '`,`'), B[1 .. -2])), B[-1];
    cat(`{`, pFq, `(`, p, `;\\,`, q, `;\\,`, z, `)}`)
end proc:

$\mathrm{latex}\left(\mathrm{hypergeom}\left(\left[a\,b\right]\,\left[c\right]\,z\right)\right)$

{\mbox{$_2$F$_1$}(a,b;\,c;\,z)}

$\mathrm{latex}\left(\mathrm{hypergeom}\left(\left[a\right]\,\left[c\right]\,z\right)\right)$

{\mbox{$_1$F$_1$}(a;\,c;\,z)}

$\mathrm{latex}\left(\mathrm{hypergeom}\left(\left[\right]\,\left[c\right]\,z\right)\right)$

{\mbox{$_0$F$_1$}(\ ;\,c;\,z)}