Oracles and truth

and you might not have heard of it before. … So what is an oracle? … Well, the term originated in a 1978 paper … by a computer scientist name William Howden … and it refers to the source of truth … that determines if the output of a system … that you currently see is right or wrong. … Now, that's all a bit abstract … so let's take a look at a specific example … to help understand it better. … We're going to look at this with a simple calculator … that we can use to calculate how much it will cost us … to park for a given amount of time. … Now, I'm going to choose some dates on here. … but for my leaving date I'm going to choose a date … Well let's see, so I click calculate, … and it gives me this error, you can't have a date … or time, that exit date, that's before … your entry date or time. … Now here's my question for you, … is this right or wrong? … I'm going to pause here for a second … and let you think about it. … Is it right or wrong? … We could say that it's right, … since it tells us that we did something …