You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: erfinv.m
    path of file: ./repos/chebfun/@chebfun
    
    the code of the file until where you have to start completion: function F = erfinv(F, varargin)
%ERFINV   Inverse error function of a CHEBFUN.
%   X = ERFINV(Y) is the inverse error function of the CHEBFUN Y. The inverse
%   error function satisfies Y = ERF(x), for -1 <= Y <= 1 and -Inf <= X <= Inf.
%
% See also ERF, ERFC, ERFCX, ERFCINV.

% Copyright 2017 by The University of Oxford and The Chebfun Developers.
% See http://www.chebfun.org/ for Chebfun information.

    
function F = erfinv(F, varargin)
%ERFINV   Inverse error function of a CHEBFUN.
%   X = ERFINV(Y) is the inverse error function of the CHEBFUN Y. The inverse
%   error function satisfies Y = ERF(x), for -1 <= Y <= 1 and -Inf <= X <= Inf.
%
% See also ERF, ERFC, ERFCX, ERFCINV.

% Copyright 2017 by The University of Oxford and The Chebfun Developers.
% See http://www.chebfun.org/ for Chebfun information.

% Input must be real:
if ( ~isreal(F) )
    error('CHEBFUN:CHEBFUN:erfinv:notreal', 'Input must be real.');
end