def cho_solve(a, b, uplo:'U')
    Lapack.call(:potrs, a, b, uplo:uplo)[0]
  end
def cho_solve(a, b, uplo:'U')
    Lapack.call(:potrs, a, b, uplo:uplo)[0]
  end
Solves a system of linear equations
     A*X = B
 with a symmetric/Hermitian positive definite matrix A
 using the Cholesky factorization
 `A = U**T*U` or `A = L*L**T` computed by Linalg.cho_fact.
 @param a [Numo::NArray] the triangular factor U or L from the
   Cholesky factorization, as computed by Linalg.cho_fact.
 @param b [Numo::NArray] the right hand side matrix B.
 @param uplo [String or Symbol] optional, default='U'. Access upper
   or ('U') lower ('L') triangle.
 @return [Numo::NArray] the solution matrix X.