AB Fuzzy Logic Implementation

I have an application that would be ideally solved with a small fuzzy logic solution. The requirements are about 5-6 inputs, 5 rules and 1 output.

I realise that some PLC suppliers have dedicated fuzzy FB's, but my preference is to implement this within an AB processor, as part of a much larger project in standard ladder.

Given time I am sure I can develop some code from scratch, but in order to avoid re-inventing wheels here I am hoping that someone can offer some advice or an example to help point me in the right direction.

I am not sure if fuzzy logic can be implemented in an AB system but the writer of this bases things using AB but you have to read all of it, its possible to use Structed Text.
http://www.patchn.com/plc_fuzzy.pdf