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

**URL:** <https://community.freefem.org/t/getting-problem-to-write-the-integral-term-in-freefem-of-oldroyd-model-of-order-one/3669>\
**Category:** General Discussion\
**Created:** [January 2, 2025, 4:22pm UTC](https://community.freefem.org/t/getting-problem-to-write-the-integral-term-in-freefem-of-oldroyd-model-of-order-one/3669 "2025-01-02T16:22:38Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![Monirul25](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.freefem.org/monirul25/32/3287_2.png) [@Monirul25](https://community.freefem.org/u/Monirul25)\
**Post date:** [January 2, 2025, 4:22pm UTC](https://community.freefem.org/t/getting-problem-to-write-the-integral-term-in-freefem-of-oldroyd-model-of-order-one/3669/1 "2025-01-02T16:22:38Z")

</div>

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

 ![eqn_one](https://canada1.discourse-cdn.com/flex030/uploads/freefem/original/2X/0/07f54af3eb4e1afb190abff82a03adfe229465f7.png)  
**Given information:**  
 ![eqn_two](https://canada1.discourse-cdn.com/flex030/uploads/freefem/original/2X/9/9a1fe4fd9b3f0c1157d6e68596adcc10a29ae13f.png)  
**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)=0.1_exp(-0.1_t).**  
Here, is the weak form( fully discrete scheme)(SIPG DG):  
 ![eqn_three](https://canada1.discourse-cdn.com/flex030/uploads/freefem/original/2X/1/1e9693b8b1a4230efb8f2113234b0533ee17de31.png)  
Here, is the bilinear form: **SIPG DG bilinear form**  
 ![SIPG bilinear](https://canada1.discourse-cdn.com/flex030/uploads/freefem/original/2X/c/c1a1e86dde673f5c177db03021de0008378ed4dd.png)

**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.