Is dependent co-arising an "IF AND ONLY IF A THEN B" relation?

"IF AND ONLY IF A THEN B" means if you get B you get A, if you get A you get B, if you don't get B you don't get A, and if you don't get A you don't get B. Does dependent co-arising have the same relation I've mentioned above? >*"From ignorance as a requisite condition come fabrications. From fabrications as a requisite condition comes consciousness. From consciousness as a requisite condition comes name-&-form..."* >*"Now from the remainderless fading & cessation of that very ignorance comes the cessation of fabrications. From the cessation of fabrications comes the cessation of consciousness. From the cessation of consciousness comes the cessation of name-&-form..."* If the answer is "yes" to the above question, as we know an Arahant has ceased the craving without remainder. Then do consciousness, name-&-form, six sense media, contact, and feeling not present in an Arahant? If these present as effects of past birth's causes, how one can escape from this cycle? If the answer is "no" to my first question, then is there another dependent co-arising which applies to Arahants? (I suppose there's no such) I know that dependent co-arising is very complex and hard to understand. But, I've got totally confused here. Please someone help me.