eclact{-}a($x$)
\\[0ex]$\,\equiv$$_{\mbox{\scriptsize def}}$$\;\;$ecl\_ind($x$;$k$,${\it test}$.$\cdot$;$a$,$b$,${\it rec}_{1}$,${\it rec}_{2}$.$\cdot$;$a$,$b$,${\it rec}_{1}$,${\it rec}_{2}$.$\cdot$;$a$,$b$,${\it rec}_{1}$,${\it rec}_{2}$.$\cdot$;$a$,${\it rec}_{1}$.$\cdot$;$a$,$n$,${\it rec}_{1}$.$a$;$a$,$n$,${\it rec}_{1}$.$\cdot$;$a$,$l$,${\it rec}_{1}$.$\cdot$)