AC_DEFUN([_AI_LIST_CONTAINS],
    [
        _aiContains()
        {
            for _ai_current1 in $1
            do
                if test "x${_ai_current1}" = "x$2"
                then
                    ifelse([$3], , :, [$3])
                    return
                fi
            done
            ifelse([$4], , :, [$4])
        }
        
        _aiContains
    ])

AC_DEFUN([_AI_LIST_ADD_PREFIX_AND_SUFFIX],
    [
        _AI_LIST_RESULT1=""
        for _ai_current2 in $1
        do
            _AI_LIST_RESULT1="${_AI_LIST_RESULT1}$2${_ai_current2}$3"
        done
        $4="${_AI_LIST_RESULT1}"
    ])

AC_DEFUN([_AI_LIST_ADD_PREFIX],
    [
        _AI_LIST_ADD_PREFIX_AND_SUFFIX([$1], [$2], [], [$3])
    ])

AC_DEFUN([_AI_LIST_ADD_SUFFIX],
    [
        _AI_LIST_ADD_PREFIX_AND_SUFFIX([$1], [], [$2], [$3])
    ])

AC_DEFUN([_AI_LIST_REVERT],
    [
        _AI_LIST_RESULT2=""
        for _ai_current3 in $1
        do
            _AI_LIST_RESULT2="${_ai_current3} ${_AI_LIST_RESULT2}"
        done
        $2="${_AI_LIST_RESULT2}"
    ])

AC_DEFUN([_AI_LIST_APPEND_WO_DUPLICATES],
    [
        _AI_LIST_RESULT3="$1"
        for _ai_current4 in $2
        do
            _AI_LIST_CONTAINS([${_AI_LIST_RESULT3}], [${_ai_current4}],
                [],
                [
                    _AI_LIST_RESULT3="${_AI_LIST_RESULT3} ${_ai_current4}"
                ])
        done
        $3="${_AI_LIST_RESULT3}"
    ])

AC_DEFUN([_AI_LIST_PREPEND_WO_DUPLICATES],
    [
        _AI_LIST_RESULT4="$1"
        _AI_LIST_REVERT([$2], _AI_LIST_ARG1)
        for _ai_current5 in ${_AI_LIST_ARG1}
        do
            _AI_LIST_CONTAINS([${_AI_LIST_RESULT4}], [${_ai_current5}],
                [],
                [
                    _AI_LIST_RESULT4="${_ai_current5} ${_AI_LIST_RESULT4}"
                ])
        done
        $3="${_AI_LIST_RESULT4}"
    ])