Recent Posts

Logic: Proofs with Quantifiers

Now we're at the stage where you're probably antsy to start actually writing proofs. Excellent! Let's get started. The main message (and it's the reason...

Logic: Uniqueness

There is another quantifier, besides existential and universal: the unique existential quantifier. Definition. The sentence is true if there is exactly one in the universe...

Logic: Quantifiers

Some sentences feel an awful lot like statements but aren't. For example, is even This is not a statement because it doesn't have a truth...

Logic in Proofs

Logic as a game of pushing symbols is fun, but our purpose with it is to construct arguments. In fact, classically an advanced education was...

Logic: Conditionals

  So far our statements haven't been very interesting. In fact most mathematical statements of interest are things like If a function is differentiable, then...

Logic: Or

Let's get another little word. Definition. Given two propositions and , the proposition (read or ) has truth value as given below: T T T...