X-Git-Url: https://git.distorted.org.uk/~mdw/catacomb/blobdiff_plain/0f00dc4c8eb47e67bc0f148c2dd109f73a451e0a..HEAD:/math/mp-fibonacci.c diff --git a/math/mp-fibonacci.c b/math/mp-fibonacci.c index 9b37ebff..1db9b21a 100644 --- a/math/mp-fibonacci.c +++ b/math/mp-fibonacci.c @@ -37,7 +37,7 @@ * %$F_{k-1} = F_{k+1} - F_k$%; in particular, %$F_{-1} = 1$% and * %$F_{-2} = -1$%.) We say that %$F_k$% is the %$k$%th Fibonacci number. * - * We work in the ring %$\ZZ[t]/(t^2 - t -1)$%. Every residue class in this + * We work in the ring %$\ZZ[t]/(t^2 - t - 1)$%. Every residue class in this * ring contains a unique representative with degree at most 1. I claim that * %$t^k = F_k t + F_{k-1}$% for all %$k$%. Certainly %$t = F_1 t + F_0$%. * Note that %$t (F_{-1} t + F_{-2}) = t (t - 1) = t^2 - t = 1$%, so the