Fixed a few typos (#2)

Fixed a few typos

Author: AntoineRondelet

libfqfft/evaluation_domain/evaluation_domain.hpp

@@ -7,13 +7,13 @@
  a choice of domain S with size ~m that has been selected so to optimize
  - computations of Lagrange polynomials, and
  - FFT/iFFT computations.
- An evaluation domain also provides other other functions, e.g., accessing
+ An evaluation domain also provides other functions, e.g., accessing
  individual elements in S or evaluating its vanishing polynomial.
 
  The descriptions below make use of the definition of a *Lagrange polynomial*,
  which we recall. Given a field F, a subset S=(a_i)_i of F, and an index idx
- in {0,...,|S-1|}, the idx-th Lagrange polynomial (wrt to subset S) is defined to be
- \f[   L_{idx,S}(z) := prod_{k \neq idx} (z - a_k) / prod_{k \neq idx} (a_{idx} - a_k)   \f]
+ in {0, ..., |S|-1}, the idx-th Lagrange polynomial (wrt to subset S) is defined to be
+ \f[   L_{idx,S}(z) := prod_{k \neq idx} [(z - a_k) / (a_{idx} - a_k)]   \f]
  Note that, by construction:
  \f[   \forall j \neq idx: L_{idx,S}(a_{idx}) = 1  \text{ and }  L_{idx,S}(a_j) = 0   \f]