Help with a Regex

[chickenlicken]

Hello, looking for some help from Regex experts

I am doing some text analysis..

It is partially working, but I end up with some contradictions and repetitions.. e.g. NOT DOG, DOG-PRESENT, or NOT CAT, CAT-PRESENT, CAT-PRESENT. 

The -PRESENT ones are better quality than the 'NOTS' so these should overrule them

I need a Regex that removes repetitions, and looks for the key word (DOG or CAT) and if -PRESENT is there, removes the NOT [KEYWORD].

Is this possible?

[binuacs]

@chickenlicken are you looking for something like this?