[Exim] Router Condition problem

List,

Im trying to get a conditional router to work in exim 4 with the condition:
condition = ${if and {\
    {if !=={$localhost_number}{3} {yes}{no}}\
    {if !{def:header_X-GForce-Host:} {yes}{no}}\
}} {yes}{no}}

basically I want to make sure that the X-GForce-Host header is not set and
localhost_number is not equal to 3...

But somewhere my logic or code is wrong.  Any hints would be appreciated :)

Thanks,

Matt