Posted to tcl by kbk at Mon May 04 14:04:05 GMT 2009view pretty

puts [apply {{f args} {tailcall {*}$f $f {*}$args}} {apply {{f x} {
    if {$x == 0} {
	expr 1
    } else {
	expr {$x * [{*}$f $f [expr {$x - 1}]]}
    }
}}} 6]