Today is my last day of my 30 day "sharing what I learn" challenge. I want to spend this last one talking about one more symbol from Teller's Logic Primer, the book on formal logic that I spoke about a week ago. That symbol happens to represent "bi-directionality" or the idea of "if and only if" and it can look like this "≡". If we remember from before, the ">" symbol represents the conditional in Teller's Logic Primer. So if we have the sentence "X>Y" that means "if X then Y". The sentence "(X>Y)&(Y>X)" is equivalent to "X≡Y". This makes this "if and only if symbol" work like the conditional, but both ways. As an example, if the sentence A represents "I like chocolate" and B represents "I will buy chocolate". If we wanted to say "if I like chocolate then I will buy chocolate" and "if I buy chocolate then I like chocolate", we could succinctly represent that as "A≡B".
Although this is the last post in this series, this isn't the end of me posting on this stream, not by a long shot. If you're interested in more notes here, check back when you can or subscribe to my RSS feed! Until next time!