mandrill logic if/else statement to provide a fallback option if condition not satisifed

I am trying to figure out mandrill conditional statements and have done a lot of reseach but cannot figure this out.

My logic looks like this:

*|IF:house=true|*
   House,  
*|END:IF|* 

*|IF:garden=true|*
    Garden,  
*|END:IF|*  

*|house!=true && garden=!true|*                                        
    House and Garden not included
*|END:IF|*   

I thought this answer would help me solve it but still cannot figure it out. I have tried all sorts of variations, but it is still not working.

Any help would be greatly appreciated.