#!/bin/bash

if ${BASH_VERSION+\:} false; then
	shopt -s extglob lastpipe expand_aliases
	shopt -u assoc_expand_once
fi
case $(command -v let) in let) ;; *) let() while ${2+\:} return "$((! ( ${1:-0} )))"; do shift; done; esac

alias \
	n='let "(n += 1) >= max" && ' \
	c='printf "%s " "$n"; n alias c="printf \$(( (n -= 1) + 1))\ ;" n=; eval c c'

set -x
n=0 max=9 command eval c echo