Key Sequence New Definitions division + division algorithm greatest common divisor prime Euclidean Algorithm Results and Their Proofs principle of induction primes there are infinitely many primes division and greatest common divisor division algorithm properties of the gcd Euclidean Algorithm and some euclid lemma linked below in fundamental theorem of arithmetic Questions for Jana Why does something being prime require that p>1. that is, why is 1 not defined as prime? Interesting Factoids