\DOC FIRST_CONV

\TYPE {FIRST_CONV : conv list -> conv}

\SYNOPSIS
Apply the first of the conversions in a given list that succeeds.

\KEYWORDS
conversional.

\DESCRIBE
{FIRST_CONV [c1,...,cn] t} returns the result of applying to the term
{t} the first conversion {ci} that succeeds (or raises {UNCHANGED})
when applied to {t}. The conversions are tried in the order
in which they are given in the list.

\FAILURE
{FIRST_CONV [c1,...,cn] t} fails if all the conversions {c1}, ...,
{cn} fail when applied to the term {t}. {FIRST_CONV cs t} also fails
if {cs} is the empty list.

\SEEALSO
Conv.ORELSEC, Conv.UNCHANGED.
\ENDDOC