I tried to upload the Matlab syms (see below) function but, for instance

syms s t

do not works.

function syms(varargin)
%SYMS Short-cut for constructing symbolic objects.
% SYMS arg1 arg2 ...
% is short-hand notation for
% arg1 = sym('arg1');
% arg2 = sym('arg2'); ...
%
% SYMS arg1 arg2 ... real
% is short-hand notation for
% arg1 = sym('arg1','real');
% arg2 = sym('arg2','real'); ...
%
% SYMS arg1 arg2 ... positive
% is short-hand notation for
% arg1 = sym('arg1','positive');
% arg2 = sym('arg2','positive'); ...
%
% SYMS arg1 arg2 ... clear
% is short-hand notation for
% arg1 = sym('arg1','clear');
% arg2 = sym('arg2','clear'); ...
%
% Each input argument must begin with a letter and must contain only
% alphanumeric characters.
%
% By itself, SYMS lists the symbolic objects in the workspace.
%
% Examples:
% syms x beta real
% is equivalent to:
% x = sym('x','real');
% beta = sym('beta','real');
%
% syms k positive
% is equivalent to:
% k = sym('k','positive');
%
% To clear the symbolic objects x and beta of 'real' or 'positive' status, type
% syms x beta clear
%
% See also SYM.

% Deprecated API:
% The 'unreal' keyword can be used instead of 'clear'.

% Copyright 1993-2008 The MathWorks, Inc.
% $Revision: 1.18.4.4 $ $Date: 2008/08/20 23:06:29 $

if nargin < 1
w = evalin('caller','whos');
k = strmatch('sym',char({w.class,''}));
disp(' ')
disp({w(k).name})
disp(' ')
return
end

n = numel(varargin);
for k = 1:n
if ~isvarname(varargin{k})
error('symbolic:sym:errmsg1','Not a valid variable name.')
end
end
reals = strcmp(varargin{n},'real');
unreals = strcmp(varargin{n},'unreal') | strcmp(varargin{n},'clear');
pos = strcmp(varargin{n},'positive');
if any(reals | unreals | pos), n = n-1; end
for k = 1:n
x = varargin{k};
if reals
assignin('caller',x,sym(x,'real'));
elseif unreals
assignin('caller',x,sym(x,'unreal'));
elseif pos
assignin('caller',x,sym(x,'positive'));
else
assignin('caller',x,sym(x));
end
end