getting compile error when i reference flashx module

I am building an ioS/Android app in Flash Builder 4.7.

I am using the TLF classes to do some advanced text handling. so import :

          import flashx.textLayout.elements.TextFlow;

          import flashx.textLayout.formats.TextLayoutFormat;

however it says "Definition... could not be found" on those two lines, so my program won't compile.

I am including in my library path "tlfRuntime.swc", but that doesn't seem to fix it.

i realize that the TLF classes are not part of Flash, so i gotta include and specify to merge into the code the class, but i swear this code used to work before I updated to SDK 3.9 beta, which I have to do because IOS7 broke all my air apps, so I am rebuilding them now, and can't remember how I got this compile before.

i downloaded the Flex SDK, but this is an AIR app, so not sure what to do with the flex stuff anyway.

I am trying to build a standalone app, so is flex even part of the equation? It sure is confusing to me how Adobe mixes air and flex, why can't they just have a single environment, with different libraries...

any help is appreciated.