fact: Definition ratCD(r1 r2 : Rat) : (nat * nat * posnat) := match (r1, r2) with | (RatIntro n1 d1, RatIntro n2 d2) => ((n1 * d2), (n2 * d1), (posnatMult d1 d2)) end.
imports: micromega.Lia List FCF.StdNat Arith Lia