\documentclass{article}
\usepackage{lisp-on-tex}
\lispinterp{%
%rocket body
(\define \rocket
  (\letM ((\count :11))
    (\lambda ()
      (\begin
        (\setB \count (\- \count :1))
        (\lispif (\< \count :0)
          (\texprint '{\small fired...}\\')
          (\lispif (\= \count :0)
            (\texprint '{\Large FIRE!}\\')
            (\texprint (\concat 'count ' (\intTOstring \count) '...\\'))))))))
(\define \MAX :15)
%LOOP function
(\define \loop
  (\lambda (\n)
    (\lispif (\= \n \MAX)
      ()
      (\begin (\rocket) (\loop (\+ \n :1))))))
}
\begin{document}
\noindent\lispinterp{(\loop :0)}
Test done.
\end{document}