You are right, I was off. On another note: I absolutely do not understand why we substitute the international mathematical symbol for cardinality (|A|) with va

You are right, I was off. On another note: I absolutely do not understand why we substitute the international mathematical symbol for cardinality (|A|) with variables we have to explain. Computer science has a math background, so we all know set theory. At least I also learned using cardinality with Big O notation in university. But for some reason industry prefers to use variables here.