Getting problem to write the integral term in FreeFem++ of Oldroyd Model of Order One

[Monirul25 (Monirul)]

Hello, all experts and respected professors

I am trying to solve DG of Oldroyd Model of Order One with Backward Euler scheme in time. I am getting problem to write the integral term in FreeFem++.

Here, is the equation

Given information:

I am trying to use it to write the code. But i am facing problem to write. Given that nu=1, gamma=delta=0.1 and then beta(t)=0.1exp(-0.1t).
Here, is the weak form( fully discrete scheme)(SIPG DG):

Here, is the bilinear form: SIPG DG bilinear form

I will very glad if i get any ideas to write the integral term(third term in above fully-discrete scheme) in FreeFem++. Thanks in advance.