2022-04-30 07:58:36 +0200 received badge ● Famous Question (source) 2016-11-04 05:01:10 +0200 received badge ● Notable Question (source) 2016-10-02 23:30:57 +0200 received badge ● Popular Question (source) 2013-11-06 13:49:05 +0200 marked best answer how to turn off symbolic sum evaluation The problem is that, unlike some other symbolic operators, the symbolic sum does not accept the hold parameter: sage: var('k n') (k, n) sage: sum(binomial(n,k),k,1,n, hold=True) TypeError: symbolic_sum() got an unexpected keyword argument 'hold'  So, we have to look at the source code and figure out how to simulate one. It is not straightforward, but here is a possible solution: sage: from sage.interfaces.maxima_lib import max_to_sr, sr_to_max, maxima_eval, max_ratsimp, max_sum, max_simplify_sum unsimplified_sum = lambda args : max_to_sr(maxima_eval([[max_ratsimp],([max_sum],[sr_to_max(SR(a)) for a in args])])) sage: further_simplify = lambda f : max_to_sr(maxima_eval([[max_ratsimp],[[max_simplify_sum],sr_to_max(f)]]))  Then, you can do: sage: var('k n') (k, n) sage: s = unsimplified_sum((binomial(n, k), k, 1, n)) ; s sum(binomial(n, k), k, 1, n) sage: further_simplify(s) 2^n - 1  Or: sage: s = unsimplified_sum((k^2,k,1,n)) ; s sum(k^2, k, 1, n) sage: further_simplify(s) 1/3*n^3 + 1/2*n^2 + 1/6*n  EDIT This issue might be fixed by trac ticket 21645. 2013-11-06 13:49:05 +0200 received badge ● Scholar (source) 2013-11-06 13:49:03 +0200 received badge ● Supporter (source) 2013-11-04 17:32:07 +0200 received badge ● Student (source) 2013-11-04 10:15:35 +0200 asked a question how to turn off symbolic sum evaluation I made some symbolic manipulation and finally... I want to save a 'sum()' in a input form (a evaluated version is horrible big). It is possible to turn off the sum evaluation in SAGE?